Medical image segmentation is a critical application of computer vision in the analysis of medical images. Its primary objective is to isolate regions of interest in medical images from the background, thereby assisting clinicians in accurately identifying lesions, their sizes, locations, and their relationships with surrounding tissues. However, compared to natural images, medical images present unique challenges, such as low resolution, poor contrast, inconsistency, and scattered target regions. Furthermore, the accuracy and stability of segmentation results are subject to more stringent requirements. In recent years, with the widespread application of Convolutional Neural Networks (CNNs) in computer vision, deep learning-based methods for medical image segmentation have become a focal point of research. This paper categorizes, reviews, and summarizes the current representative methods and research status in the field of medical image segmentation. A comparative analysis of relevant experiments is presented, along with an introduction to commonly used public datasets, performance evaluation metrics, and loss functions in medical image segmentation. Finally, potential future research directions and development trends in this field are predicted and analyzed.

Bowel cancer is the third most common malignancy of tumors and one of the major causes of cancer-related death. Bowel precancerous conditions can develop without any symptoms, which either makes it difficult for early diagnosis or poses a poor prognosis/gloomy relapse. This study aimed to investigate the effects of Bifidobacterium animalis subsp. lactis TCI604 (B. lactis) on inflammatory responses, gut microbiome, and protectiveness against azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colonic precancerous lesions. The AOM/DSS-induced colonic precancerous lesion murine model was studied with 24 female C57BL/6 J mice assigned to the control group, AOM/DSS-induced colonic precancerous lesion group (AOM/DSS), AOM/DSS treated with B. lactis probiotic group (B. lactis P), and AOM/DSS treated with B. lactis cell-free supernatant group (B. lactis S). The results showed that both B. lactis P and B. lactis S could attenuate AOM/DSS-induced body weight loss and intestine damage, reduce aberrant crypt foci (ACF) and the formation of colonic polyps, and significantly inhibit pro-inflammatory cytokines and the NF-κB signaling pathway, in which the B. lactis S group outperformed others. Further analysis using 16S rDNA sequencing suggested that both B. lactis P and B. lactis S optimize gut microbiota. Several bacteria, including Muribaculaceae, Prevotellaceae_UCG-001, Anaerostipes, Ruminococcaceae, Mucispirillum, Clostridia_UCG-014, and Clostridia_vadinBB60 that were known in close relation to colonic precancerous lesions, were sequenced at taxonomic level. Our results indicated that both B. lactis P and B. lactis S improved AOM/DSS-induced colonic precancerous lesions by regulating inflammation as well as optimizing gut microbiota, thereby establishing reciprocally cooperative net benefits between probiotics/postbiotics and mice with colonic precancerous lesions. KEY POINTS: • Prophylactic administration of probiotic and postbiotic of B. lactis is capable of alleviating the AOM/DSS-induced body weight loss and colon shortening, as well as diminishing the development of colonic precancerous lesions, such as the formation of ACF and colonic polyps, in an AOM/DSS mouse model • Either probiotic or postbiotic of B. lactis has a positive role in mediating immune imbalance and colonic inflammation via suppression of inflammatory immune cells, pro-inflammatory cytokines, and the NF-κB signaling pathway • AOM/DSS-induced dysbiosis can be reversed with the probiotic and postbiotic of B. lactis supplementation.

Iron deficiency anaemia (IDA) related to occult gastrointestinal tract (GIT) blood loss is associated with high rates of GIT malignancies. Major society guidelines recommend bidirectional endoscopic evaluation for all men and post-menopausal women with newly diagnosed, unexplained IDA. However, in patients prescribed direct oral anticoagulants (DOACs), the endoscopic yield, specifically the rate of high-risk findings, including colorectal cancers (CRCs) and advanced adenomas (AAs), is unknown.

Our aim is to determine the endoscopic yield, specifically the prevalence of these high-risk findings in patients presenting with new-onset unexplained IDA while on a DOAC.

This is a single-centre, retrospective analysis performed at a tertiary hospital in Australia. Between January 2015 and July 2019, 178 consecutive patients underwent endoscopic evaluation for IDA while prescribed a DOAC. Patient demographics, laboratory data, medications and endoscopic findings were summarised and compared by diagnostic yield. Associations were explored using logistic regression analysis.

CRCs were present in 2/178 (1.1% (95% confidence interval (CI): 0.1-4.0)) patients. AAs were found in 35/178 (19.6% (95% CI: 14.1-26.3)) patients. The most common AAs were tubular adenomas (45.7%), tubulovillous (31.4%) and sessile serrated adenomas (14.2%). Older age (P = 0.013) and lower ferritin levels (P = 0.009) were associated with the presence of high-risk findings.

In patients presenting with new-onset, unexplained IDA while on a DOAC, the prevalence of CRCs is lower than previously reported in studies involving populations not prescribed DOACs. Conversely, there is a higher incidence of AAs, including high-risk histological features, such as tubulovillous adenomas and sessile serrated polyps.

The vast majority of colon cancers occur in pre-existing adenomas. Little is known about the impact of adenoma type on behavior and outcome of subsequent carcinomas. The present study aimed to assess characteristics, behavior, and outcome of colon adenocarcinoma based on histologic type of pre-existing adenoma.

US-National Cancer Database was searched between 2005 and 2019 for patients with colonic adenocarcinoma with known adenoma type who underwent colectomy. Patients were divided into 3 groups according to type of adenoma in which carcinoma developed: tubular adenoma (TA), villous adenoma (VA), and tubulovillous adenoma (TVA)-associated carcinomas. The main outcome of the study was 5-year overall survival (OS).

66,854 patients were included. 79.3% of carcinomas originated from TVA, 10.2% from VA, and 0.5% from TA. Patients with adenocarcinoma in VA were more often female whereas carcinomas in TA affected patients of Asian race more often. Approximately one-third of carcinomas in villous and tubulovillous adenomas were in the cecum whereas one-third of carcinomas in tubular adenomas were in the sigmoid colon. More TA-associated carcinomas were of clinical T1-2 stage (30.2% vs. 20.8%; P < .001), clinical N0 stage (69% vs. 62.2%, P < .001), and high grade (15.9% vs. 11.5%, P < .001) compared to VA-associated carcinomas. Patients with TA-associated carcinomas had longer mean OS than patients with VA and TVA-associated carcinomas (130.1 vs. 116.9 vs. 123.5 months, P < .0001).

Adenocarcinomas that arose in TA had more T1-2 stage and N0 stage, higher grade, and longer OS than did adenocarcinomas that arose in VA and TVA.

The dysregulation of intestinal microbiota has been implicated in the pathogenesis of colorectal cancer (CRC). However, the utilization of intestinal microbiota for identify the lesions in different procedures in CRC screening populations remains limited.

A total of 529 high-risk individuals who underwent CRC screening were included, comprising 13 advanced adenomas (Aade), 5 CRC, 59 non-advanced adenomas (Nade), 129 colon polyps (Pol), 99 cases of colorectal inflammatory disease (Inf), and 224 normal controls (Nor). 16S rRNA gene sequencing was used to profile the intestinal microbiota communities. The Gut Microbiota Health Index (GMHI) and average variation degree (AVD) were employed to assess the health status of the different groups.

Our findings revealed that the Nor group exhibited significantly higher GMHIs and the lowest AVD compared to the four Lesion groups. The model incorporating 13 bacterial genera demonstrated optimal efficacy in distinguishing CRC and Aade from Nor, with an area under the curve (AUC) of 0.81 and a 95% confidence interval (CI) of 0.72 to 0.89. Specifically, the 55 bacterial genera combination model exhibited superior performance in differentiating CRC from Nor (AUC 0.98; 95% CI, 0.96-1), the 25 bacterial genera combination showed superior performance in distinguishing Aade from Nor (AUC 0.95). Additionally, the 27 bacterial genera combination demonstrated superior efficacy in differentiating Nade from Nor (AUC 0.82). The 13 bacterial genera combination exhibited optimal performance in distinguishing Inf from Nor (AUC 0.71).

Our study has identified specific microbial biomarkers that can differentiate between colorectal lesions and healthy individuals. The intestinal microbiota markers identified may serve as valuable tools in community-based CRC screening programs.

Introduction Colorectal cancer (CRC) represents a major global health burden, significantly impacting mortality rates and healthcare systems worldwide. CRC screening through colonoscopy enables early detection and removal of precancerous polyps. While standard polypectomy suffices for small polyps, larger ones require endoscopic mucosal resection (EMR). Though post-EMR surveillance is crucial for preventing recurrence, it remains unclear whether follow-up by general gastroenterologists yields comparable outcomes to surveillance by interventional specialists. This distinction carries significant implications for resource allocation, particularly given the limited availability of interventional gastroenterologists whose expertise is needed for other complex procedures. Our study examines this unexplored question by comparing post-EMR surveillance outcomes between these provider groups. Methods We conducted a retrospective study at the Saint Louis Veterans Affairs (VA) Health Care System of patients presenting for follow-up of colorectal polyp EMR between January 2019 and December 2022. Pre-defined variables extracted from the electronic medical record system were then analyzed to discern significant differences between general and interventional gastroenterologists' outcomes. The primary outcome includes the rate of biopsy of scars after EMR between both groups. Additional outcomes include the number of polyps detected, detection of residual tissue at the EMR site, EMR site recurrence requiring polypectomy and mode of polypectomy, recommended surveillance interval suggested by the endoscopist, and the pathology of the EMR site biopsy. Results A total of 59 (N = 59) patients (median age: 67, mean age: 66.5 ± 6.6 years) met the inclusion criteria of our study. General gastroenterologists were more likely to biopsy the EMR site compared to interventional gastroenterologists (65% vs. 40%, p = 0.047). There was no difference in overall pathology detected when comparing general and interventional gastroenterologists (p = 0.074). While no EMR site biopsies were obtained in 16 patients (27.1%), there were no differences in the pathology of patients undergoing biopsy of the scar. Additionally, no significant differences were found in the Boston Bowel Preparation Score, number of polyps detected, detection of residual tissue at the EMR site, EMR site recurrence requiring polypectomy, or recommended surveillance interval. Conclusion Our study provides evidence that the outcomes of post-EMR follow-up are largely comparable between general and interventional gastroenterologists. Although general gastroenterologists exhibit higher rates of EMR site biopsy, the associated pathology shows no significant difference.

Effective bowel cancer screening is freely available in Australia, however, there are inequities in utilisation amongst non-English speakers at home. This study estimates the health impacts and cost-effectiveness of recruitment interventions targeted at Arabic and Mandarin speaking populations in Victoria, Australia to increase bowel cancer screening participation.

A Markov microsimulation model simulated the development of bowel cancer, considering National Bowel Cancer Screening Program participation rates. Culturally specific recruitment interventions e.g., community education and tailored paid media for 50-74-year-olds were compared to usual practice. A cost-utility analysis was conducted over a 50-year time horizon from a healthcare perspective, to estimate the cost per quality-adjusted life year (QALY) based on plausible effectiveness levels. Costs are in 2019 Australian dollars.

Intervention costs were $6.90 per person for the Arabic speaking group and $3.10 for Mandarin speakers. The estimated cost/QALY was $2,781 (95% uncertainty interval [UI]: $2,144─$3,277) when screening increased by 0.2% in the Arabic group, and an estimated 5-6 additional adenoma and cancer cases were detected. In the Mandarin group, the estimated cost/QALY was $1,024/QALY (95%UI: $749─$1,272) when screening increased by 1.1%, and an estimated 18-23 additional adenoma and cancer cases were detected.

Culturally specific recruitment interventions to increase bowel cancer screening are inexpensive and likely to be cost-effective. Improvements in capturing language spoken at home by the National program would facilitate more precise estimates of the effectiveness and cost-effectiveness of these interventions.

Colorectal cancer is a leading cause of global mortality and presents a significant barrier to improving life expectancy. The primary objective of this study was to discern a unique differentially expressed gene (DEG) that exhibits a strong association with colorectal cancer. By achieving this goal, the research aims to contribute valuable insights to the field of translational medicine. We performed analysis of colorectal cancer microarray and the TCGA colon adenoma carcinoma (COAD) datasets to identify DEGs associated with COAD and common DEGs were selected. Furthermore, a pan-cancer analysis encompassing 33 different cancer types was performed to identify differential genes significantly expressed only in COAD. Then, comprehensively in-silico analysis including gene set enrichment analysis, constructing Protein-Protein interaction, co-expression, and competing endogenous RNA (ceRNA) networks, investigating the correlation between tumor-immune signatures in distinct tumor microenvironment and also the potential interactions between the identified gene and various drugs was executed. Further, the candidate gene was experimentally validated in tumoral colorectal tissues and colorectal adenomatous polyps by qRael-Time PCR. GUCA2A emerged as a significant DEG specific to colorectal cancer (|log2FC|> 1 and adjusted q-value < 0.05). Importantly, GUCA2A exhibited excellent diagnostic performance for COAD, with a 99.6% and 78% area under the curve (AUC) based on TCGA-COAD and colon cancer patients. In addition, GUCA2A expression in adenomatous polyps equal to or larger than 5 mm was significantly lower compared to smaller than 5 mm. Moreover, low expression of GUCA2A significantly impacted overall patient survival. Significant correlations were observed between tumor-immune signatures and GUCA2A expression. The ceRNA constructed included GUCA2A, 8 shared miRNAs, and 61 circRNAs. This study identifies GUCA2A as a promising prognostic and diagnostic biomarker for colorectal cancer. Further investigations are warranted to explore the potential of GUCA2A as a therapeutic biomarker.

Automatic polyp segmentation in endoscopic images is critical for the early diagnosis of colorectal cancer. Despite the availability of powerful segmentation models, two challenges still impede the accuracy of polyp segmentation algorithms. Firstly, during a colonoscopy, physicians frequently adjust the orientation of the colonoscope tip to capture underlying lesions, resulting in viewpoint changes in the colonoscopy images. These variations increase the diversity of polyp visual appearance, posing a challenge for learning robust polyp features. Secondly, polyps often exhibit properties similar to the surrounding tissues, leading to indistinct polyp boundaries. To address these problems, we propose a viewpoint-aware framework named VANet for precise polyp segmentation. In VANet, polyps are emphasized as a discriminative feature and thus can be localized by class activation maps in a viewpoint classification process. With these polyp locations, we design a viewpoint-aware Transformer (VAFormer) to alleviate the erosion of attention by the surrounding tissues, thereby inducing better polyp representations. Additionally, to enhance the polyp boundary perception of the network, we develop a boundary-aware Transformer (BAFormer) to encourage self-attention towards uncertain regions. As a consequence, the combination of the two modules is capable of calibrating predictions and significantly improving polyp segmentation performance. Extensive experiments on seven public datasets across six metrics demonstrate the state-of-the-art results of our method, and VANet can handle colonoscopy images in real-world scenarios effectively. The source code is available at https://github.com/1024803482/Viewpoint-Aware-Network.

Background/Objectives: Dysfunctions of metabolic syndrome (MetS) have been identified as a significant risk factor for colorectal cancer (CRC). However, current colon cancer guidelines do not classify patients with MetS as high risk, thereby leaving these individuals vulnerable. Consequently, we explored the relationship between MetS, its individual components, and the development of CRC in a cohort of patients with MetS to assess the necessity for CRC screening in these individuals. Methods: This study included patients ages 18 and older that received a service from the Marshall-Health (MH) practice plan, Cabell-Huntington Hospital (CHH), MU/JCESOM's Edwards Comprehensive Cancer Center (ECCC), or the University of Kentucky HealthCare (UKHC) system between 2010 and 2018. We implemented log-binomial regression models to assess the individual and collective effects of MetS components after adjusting other CRC risk factors. Results: Given that CRC prevalence increases in the older population (aged 65 years and above), and that multiple components of MetS are observed within the same population, we analyzed the concurrent impact of all MetS components on CRC. Log-binomial regression models were implemented to assess the risk of CRC due to MetS components after adjusting other risk factors. Conclusions: We identified specific components that markedly increased CRC risk, suggesting that individuals with these components should be prioritized for early screening. These findings could significantly influence early CRC screening protocols, with the ultimate aim to reduce mortality associated with the disease.

Colonic adenomas are considered a precursor of colorectal cancer. A 75-year-old woman had a history of post-operation left breast cancer. She received an excision when the left chest wall recurred. A later FDG PET/CT scan revealed a focal intense FDG accumulation in the sigmoid, a focal mild FDG uptake in the pericolic lymph node, and a focal increased FDG accumulation in the transverse colon. A delayed FDG PET/CT scan after the per-rectal administration of the laxative-augmented contrast medium revealed a filling defect with persistent FDG uptake in the sigmoid and transverse colon and mild FDG uptake in the pericolic lymph node. In addition, more lesions were observed in the rectum and descending colon. The pathology reports showed sigmoid adenocarcinoma with lymph node metastasis, and adenomas in the transverse colon, descending colon, and rectum.

Colorectal polyps, which are characterized by a high recurrence rate, represent preneoplastic conditions of the intestine. Due to unclear mechanisms of pathogenesis, first-line therapies for non-hereditary recurrent colorectal polyps are limited to endoscopic resection. Although recent studies suggest a mechanistic link between intestinal dysbiosis and polyps, the exact compositions and roles of bacteria in the mucosa around the lesions, rather than feces, remain unsettled.

To clarify the composition and diversity of bacteria in the mucosa surrounding or 10 cm distal to recurrent intestinal polyps.

Mucosal samples were collected from four patients consistently with adenomatous polyps (Ade), seven consistently with non-Ade (Pol), ten with current Pol but previous Ade, and six healthy individuals, and bacterial patterns were evaluated by 16S rDNA sequencing. Linear discriminant analysis and Student's t-tests were used to identify the genus-level bacteria differences between groups with different colorectal polyp phenotypes. Pearson's correlation coefficients were used to evaluate the correlation between intestinal bacteria at the genus level and clinical indicators.

The results confirmed a decreased level of probiotics and an enrichment of pathogenic bacteria in patients with all types of polyps compared to healthy individuals. These changes were not restricted to the mucosa within 0.5 cm adjacent to the polyps, but also existed in histologically normal tissue 10 cm distal from the lesions. Significant differences in bacterial diversity were observed in the mucosa from individuals with normal conditions, Pol, and Ade. Increased abundance of Gram-negative bacteria, including Klebsiella, Plesiomonas, and Cronobacter, was observed in Pol group and Ade group, suggesting that resistance to antibiotics may be one risk factor for bacterium-related harmful environment. Meanwhile, age and gender were linked to bacteria changes, indicating the potential involvement of sex hormones.

These preliminary results support intestinal dysbiosis as an important risk factor for recurrent polyps, especially adenoma. Targeting specific pathogenic bacteria may attenuate the recurrence of polyps.

The incidence and mortality of colorectal cancer (CRC) have decreased through regular screening colonoscopy, surveillance, and endoscopic treatment. However, CRC can still be diagnosed after negative colonoscopy. Such CRC is called interval CRC and accounts for 1.8-9.0% of all CRC cases. Most cases of interval CRC originate from missed lesions and incompletely resected lesions. Interval CRC can be minimized by improving the quality of colonoscopy. This has led to a growing interest in and demand for high-quality colonoscopy. It is important to reduce the risk of CRC and its associated mortality by improving the quality of colonoscopy. In this review article, we provide an overview of colonoscopy quality indicators, including bowel preparation adequacy, the cecal intubation rate, the adenoma detection rate, the colonoscopy withdrawal time, appropriate polypectomy, and complication of the procedure. Because colonoscopy is a highly endoscopist-dependent procedure, colonoscopists should be well-acquainted with quality indicators and strive to apply them in daily clinical practice for the prevention of CRC.

Colorectal cancer is the second most common cause of cancer death worldwide. Screening colonoscopy is a very effective measure to prevent colorectal cancer and can reduce mortality at the population level. However, the participation rates of screening programs are low.To provide easily accessible information on screening colonoscopy and to increase the participation rates of screening programs, we developed a questionnaire for asymptomatic patients based on the German guidelines to assess the indication for screening colonoscopy. We evaluated the questionnaire with reference to the indications given by specialists in gastroenterology.

Patients who visited a specialist in gastroenterology in an outpatient clinic of a tertiary hospital for other reasons than a colonoscopy were eligible for the study. A maximum of seven questions to assess the indication for screening colonoscopy were answered by the patients. Afterward, the indication for screening colonoscopy was given or not by a specialist in gastroenterology. The accuracy of the questionnaire was measured in terms of sensitivity, specificity, and predictive values.

In total, 335 patients were included in the analyses, of whom 50 and 285 patients were given and were not given an indication for screening colonoscopy by the specialists, respectively. In 0/50 patients, the questionnaire was false negative and in 8/285 patients false positive. Thus, the questionnaire had a sensitivity of 100% (95% confidence interval: 93-100%), a specificity of 97% (95-99%), a negative predictive value of 100% (99-100%), and a positive predictive value of 86% (75-94%).A subgroup analysis including patients who had never had a colonoscopy (n=109) showed comparable results: sensitivity of 100% (92-100%), specificity of 92% (83-97%), negative predictive value of 100% (94-100%), and positive predictive value of 90% (87-97%).

The self-assessment questionnaire for asymptomatic individuals to assess the recommendation for screening colonoscopy is very sensitive and specific compared to a specialist in gastroenterology.The questionnaire can be found at: https://www.interdisziplinaere-endoskopie.mri.tum.de/de/infos-patienten/index.php.

One goal of colorectal cancer (CRC) screening is to prevent CRC incidence by removing precancerous colonic polyps, which are detected in up to 50% of screening examinations. Yet, the lifetime risk of CRC is 3.9%-4.3%, so it is clear that most of these individuals with polyps would not develop CRC in their lifetime. It is, therefore, a challenge to determine which individuals with polyps will benefit from follow-up, and at what intervals. There is some evidence that individuals with advanced polyps, based on size and histology, benefit from intensive surveillance. However, a large proportion of individuals will have small polyps without advanced histologic features (ie, "nonadvanced"), where the benefits of surveillance are uncertain and controversial. Demand for surveillance will further increase as more polyps are detected due to increased screening uptake, recent United States recommendations to expand screening to younger individuals, and emergence of polyp detection technology. We review the current understanding and clinical implications of the natural history, biology, and outcomes associated with various categories of colon polyps based on size, histology, and number. Our aims are to highlight key knowledge gaps, specifically focusing on certain categories of polyps that may not be associated with future CRC risk, and to provide insights to inform research priorities and potential management strategies. Optimization of CRC prevention programs based on updated knowledge about the future risks associated with various colon polyps is essential to ensure cost-effective screening and surveillance, wise use of resources, and inform efforts to personalize recommendations.

The English Bowel Cancer Screening Programme detects colorectal cancers and premalignant polyps in a faecal occult blood test-positive population. The aim of this work is to describe the detection rates and characteristics of adenomas within the programme, identify predictive factors influencing the presence or absence of carcinoma within adenomas and identify the factors predicting the presence of advanced colonic neoplasia in different colon segments.

The Bowel Cancer Screening System was retrospectively searched for polyps detected during colonoscopies between June 2006 and June 2012, at which time a guaiac test was being used. Data on size, location and histological features were collected, and described. Univariate and multivariate analyses were used to determine the significant factors influencing the development of carcinoma within an adenoma.

A total of 229 419 polyps were identified; after exclusions 136 973 adenomas from 58 334 patients were evaluated. Over half were in the rectum or sigmoid colon. Subcentimetre adenomas accounted for 69.8% of the total. The proportion of adenomas containing advanced histological features increased with increasing adenoma size up to 35 mm, then plateaued. A focus of carcinoma was found in 2282 (1.7%) adenomas, of which 95.6% were located distally. Carcinoma was identified even in diminutive adenomas (0.1%). The proportion of adenomas containing cancer was significantly higher in women than men (2.0% vs. 1.5%, p < 0.001).

This national, prospectively captured dataset adds robust information about histological features of adenomas that convey an increased risk for colorectal cancer, and identifies caecal adenomas, high-grade dysplasia, increasing adenoma size, distal location and female sex as independent risk factors associated with carcinoma.

For many cancers there are only a few well-established risk factors. Here, we use summary data from genome-wide association studies (GWAS) in a Mendelian randomisation (MR) phenome-wide association study (PheWAS) to identify potentially causal relationships for over 3,000 traits. Our outcome datasets comprise 378,142 cases across breast, prostate, colorectal, lung, endometrial, oesophageal, renal, and ovarian cancers, as well as 485,715 controls. We complement this analysis by systematically mining the literature space for supporting evidence. In addition to providing supporting evidence for well-established risk factors (smoking, alcohol, obesity, lack of physical activity), we also find sex steroid hormones, plasma lipids, and telomere length as determinants of cancer risk. A number of the molecular factors we identify may prove to be potential biomarkers. Our analysis, which highlights aetiological similarities and differences in common cancers, should aid public health prevention strategies to reduce cancer burden. We provide a R/Shiny app to visualise findings.

Endoscopists have low adherence to guideline-recommended colonoscopy surveillance intervals. We performed a cluster-randomized single-blind pilot trial in Winnipeg, Canada, to assess the effectiveness of a newly developed digital application tool that computes guideline-recommended follow-up intervals.

Participant endoscopists were randomized to either receive access to the digital application (intervention group) or not receive access (control group). Pathology reports and final recommendations for colonoscopies performed in the 1-4 months before randomization and 3-7 months postrandomization were extracted. Generalized estimating equation models were used to determine whether the access to the digital application predicted guideline congruence.

We included 15 endoscopists in the intervention group and 14 in the control group (of 42 eligible endoscopists in the city), with 343 patients undergoing colonoscopy before randomization and 311 postrandomization. Endoscopists who received the application made guideline-congruent recommendations 67.6% of the time before randomization and 76.1% of the time after randomization. Endoscopists in the control group made guideline-congruent recommendations 72.4% and 72.9% of the time before and after randomization, respectively. Endoscopists in the intervention group trended to have an increase in guideline adherence comparing postintervention with preintervention (odds ratio [OR]: 1.50, 95% confidence interval [CI] 0.82-2.74). By contrast, the control group had no change in guideline adherence (OR: 1.07, 95% CI 0.50-2.29). Endoscopists in the intervention group with less than median guideline congruence prerandomization had a significant increase in guideline-congruent recommendations postrandomization.

An application that provides colonoscopy surveillance intervals may help endoscopists with guideline congruence, especially those with a lower preintervention congruence with guideline recommendations ( ClincialTrials.gov number, NCT04889352).

Background The natural history of colorectal polyps is not well characterized due to clinical standards of care and other practical constraints limiting in vivo longitudinal surveillance. Established CT colonography (CTC) clinical screening protocols allow surveillance of small (6-9 mm) polyps. Purpose To assess the natural history of colorectal polyps followed with CTC in a clinical screening program, with histopathologic correlation for resected polyps. Materials and Methods In this retrospective study, CTC was used to longitudinally monitor small colorectal polyps in asymptomatic adult patients from April 1, 2004, to August 31, 2020. All patients underwent at least two CTC examinations. Polyp growth patterns across multiple time points were analyzed, with histopathologic context for resected polyps. Regression analysis was performed to evaluate predictors of advanced histopathology. Results In this study of 475 asymptomatic adult patients (mean age, 56.9 years ± 6.7 [SD]; 263 men), 639 unique polyps (mean initial diameter, 6.3 mm; volume, 50.2 mm3) were followed for a mean of 5.1 years ± 2.9. Of these 639 polyps, 398 (62.3%) underwent resection and histopathologic evaluation, and 41 (6.4%) proved to be histopathologically advanced (adenocarcinoma, high-grade dysplasia, or villous content), including two cancers and 38 tubulovillous adenomas. Advanced polyps showed mean volume growth of +178% per year (752% per year for adenocarcinomas) compared with +33% per year for nonadvanced polyps and -3% per year for unresected, unretrieved, or resolved polyps (P < .001). In addition, 90% of histologically advanced polyps achieved a volume of 100 mm3 and/or volume growth rate of 100% per year, compared with 29% of nonadvanced and 16% of unresected or resolved polyps (P < .001). Polyp volume-to-diameter ratio was also significantly greater for advanced polyps. For polyps observed at three or more time points, most advanced polyps demonstrated an initial slower growth interval, followed by a period of more rapid growth. Conclusion Small colorectal polyps ultimately proving to be histopathologically advanced neoplasms demonstrated substantially faster growth and attained greater overall size compared with nonadvanced polyps. Clinical trial registration no. NCT00204867 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Dachman in this issue.

The CT Colonography Reporting and Data System (C-RADS) has withstood the test of time and proven to be a robust classification scheme for CT colonography (CTC) findings. C-RADS version 2023 represents an update on the scheme used for colorectal and extracolonic findings at CTC. The update provides useful insights gained since the implementation of the original system in 2005. Increased experience has demonstrated confusion on how to classify the mass-like appearance of the colon consisting of soft tissue attenuation that occurs in segments with acute or chronic diverticulitis. Therefore, the update introduces a new subcategory, C2b, specifically for mass-like diverticular strictures, which are likely benign. Additionally, the update simplifies extracolonic classification by combining E1 and E2 categories into an updated extracolonic category of E1/E2 since, irrespective of whether a finding is considered a normal variant (category E1) or an otherwise clinically unimportant finding (category E2), no additional follow-up is required. This simplifies and streamlines the classification into one category, which results in the same management recommendation.

The natural history of small polyps is not well established and rests on limited evidence from barium enema studies decades ago. Patients with one or two small polyps (6-9 mm) at screening CT colonography (CTC) are offered CTC surveillance at 3 years but may elect immediate colonoscopy. This practice allows direct observation of the growth of subcentimetre polyps, with histopathological correlation in patients undergoing subsequent polypectomy.

Of 11 165 asymptomatic patients screened by CTC over a period of 16.4 years, 1067 had one or two 6-9 mm polyps detected (with no polyps ≥10 mm). Of these, 314 (mean age, 57.4 years; M:F, 141:173; 375 total polyps) elected immediate colonoscopic polypectomy, and 382 (mean age 57.0 years; M:F, 217:165; 481 total polyps) elected CTC surveillance over a mean of 4.7 years. Volumetric polyp growth was analysed, with histopathological correlation for resected polyps. Polyp growth and regression were defined as volume change of ±20% per year, with rapid growth defined as +100% per year (annual volume doubling). Regression analysis was performed to evaluate predictors of advanced histology, defined as the presence of cancer, high-grade dysplasia (HGD) or villous components.

Of the 314 patients who underwent immediate polypectomy, 67.8% (213/314) harboured adenomas, 2.2% (7/314) with advanced histology; no polyps contained cancer or HGD. Of 382 patients who underwent CTC surveillance, 24.9% (95/382) had polyps that grew, while 62.0% (237/382) remained stable and 13.1% (50/382) regressed in size. Of the 58.6% (224/382) CTC surveillance patients who ultimately underwent colonoscopic resection, 87.1% (195/224) harboured adenomas, 12.9% (29/224) with advanced histology. Of CTC surveillance patients with growing polyps who underwent resection, 23.2% (19/82) harboured advanced histology vs 7.0% (10/142) with stable or regressing polyps (OR: 4.0; p<0.001), with even greater risk of advanced histology in those with rapid growth (63.6%, 14/22, OR: 25.4; p<0.001). Polyp growth, but not patient age/sex or polyp morphology/location were significant predictors of advanced histology.

Small 6-9 mm polyps present overall low risk to patients, with polyp growth strongly associated with higher risk lesions. Most patients (75%) with small 6-9 mm polyps will see polyp stability or regression, with advanced histology seen in only 7%. The minority of patients (25%) with small polyps that do grow have a 3-fold increased risk of advanced histology.

Background Colorectal cancer most commonly affects the elderly population. Post-colorectal cancer surveillance aims to reduce cancer incidence and mortality, but its necessity and effectiveness are debated, especially in the elderly population. This study explores the relevance of computer tomography (CT) and colonoscopy surveillance in patients aged 75 and over who have undergone curative resection for colorectal cancer. Methods A retrospective analysis of prospectively collected data was conducted on patients aged 75 and over who had undergone surgical resection of colorectal cancer between November 2014 and August 2021. Data on demographics, treatment, survival, and surveillance were gathered from electronic patient records. The primary outcome was adherence to follow-up colonoscopy and CT-scan surveillance following surgery. Results A total of 417 patients underwent colorectal cancer surgery, with 334 included for analysis. The cohort had an average age of 81 years, with the majority receiving laparoscopic surgery and primary anastomosis. Twelve-month CT surveillance showed normal results in 281 patients (91.8%), while 24-month CT surveillance demonstrated normal findings in 244 patients (88.7%). Only 175 patients (52.4%) had colonoscopy follow-up, with 94 (53.7%) showing normal results, 74 (42.3%) demonstrating benign polyps, and two patients (1.1%) having histologically proven cancer. Reasons for not undergoing colonoscopy included declining invitations (30 patients, 19.1%) and being too frail (45 patients, 28.7%). Conclusion This study reinforces the notion that colonoscopy surveillance for patients over the age of 75 may have limited benefits. In an ageing population, the benefits of surveillance in terms of early detection of recurrence must be balanced against the risks of harm from the procedure, the availability of further management, cost-effectiveness, and patient preferences. An individualised approach should be adopted, potentially with colonoscopy surveillance only recommended in patients of higher risk (extramural venous invasion (EMVI)) and a low frailty score with a life expectancy over 10 years.

Inflammatory cells within the tumour microenvironment are the driving forces behind colorectal cancer (CRC) tumourigenesis. Understanding the different pathways involved in CRC carcinogenesis paves the way for effective repurposing of drugs for cancer prevention. Emerging data from preclinical and clinical studies suggest that, due to their antiproliferative and anti-inflammatory properties, phosphodiesterase-5 inhibitors (PDE5i) might have an anticancer effect. The aim of this study was to clarify through systematic review and meta-analysis of published peer-reviewed studies whether an association exists between PDE5i use and CRC risk.

This study was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Prospective registration was performed on PROSPERO (CRD42022372925). A systematic review was performed for studies reporting CRC and advanced colorectal polyp incidence in PDE5i 'ever-users' and PDE5i 'never-users'. Meta-analysis was performed using RevMan version 5.

Four observational cohort studies and two case-control studies, comprising 995 242 patients were included in the final analysis, of whom 347 126 were PDE5i ever-users. Patients who were PDE5i ever-users had a significantly lower incidence of CRC or advanced colorectal polyps than never-users (OR 0.88, CI 0.79-0.98, p = 0.02). To examine the primary preventative role of PDE5i, subgroup analysis of four studies including patients without a previous history of CRC found that use of PDE5i was associated with a lower incidence of CRC (OR 0.85, CI 0.75-0.95, p = 0.005, I2  = 64%). There was no significant temporal relationship found between PDE5i use and CRC risk as both current users and previous users had a significantly lower incidence of CRC than never-users.

Our study found a significant anticancer effect of PDE5i, as shown by a reduced risk of CRC in the context of both primary and secondary CRC prevention.

Colorectal polyp is known a precursor of colorectal cancer (CRC) that holds an increased risk for progression to CRC. Circulating cell-free DNA (cfDNA) methylation has shown favorable performance in the detection and monitoring the malignant progression in a variety of cancers.

To discover cfDNA methylation markers for the diagnosis of CRC, we first performed a genome-wide analysis between eight CRC and eight polyp tissues using the Infinium HumanMethylationEPIC BeadChip. We identified 7008 DMCs, and after filtering, we validated 39 DMCs by MethylTarget sequencing in 62 CRC and 56 polyp tissues. A panel of four CpGs (cg04486886, cg06712559, cg13539460, and cg27541454) was selected as the methylation marker in tissue by LASSO and random forest models. A diagnosis prediction model was built based on the four CpGs, and the methylation diagnosis score (md-score) can effectively discriminate tissues with CRC from polyp patients (AUROC > 0.9). Finally, the cg27541454 was confirmed hypermethylated in CRC (AUC = 0.85) in the plasma validation cohort.

Our findings suggest that the md-score could robustly detect CRC from polyp tissues, and cg27541454 may be a promising candidate noninvasive biomarker for CRC early diagnosis.

The benefits from colorectal cancer (CRC) screening may take 10 to 15 years to accrue. Therefore, screening is recommended for older adults who are in good health.

To determine the number of screening colonoscopies done in patients older than 75 years with a life expectancy of fewer than 10 years, diagnostic yield, and associated adverse events within 10 days and 30 days of the procedure.

This cross-sectional study with a nested cohort between January 2009 and January 2022 in an integrated health system assessed asymptomatic patients older than 75 years who underwent screening colonoscopy in the outpatient setting. Reports with incomplete data, any indication other than screening, patients who had a colonoscopy within the previous 5 years, and patients with a personal history of inflammatory bowel disease or CRC were excluded.

Life expectancy based on a prediction model from previous literature.

The primary outcome was the percentage of screened patients who had limited (<10 years) life expectancy. Other outcomes included colonoscopy findings and adverse events that developed within 10 days and 30 days of the procedure.

A total of 7067 patients older than 75 years were included. The median (IQR) age was 78 (77-79) years, 3967 (56%) were women, and 5431 (77%) were White with an average of 2 comorbidities (taken from a select group of comorbidities). The proportion of colonoscopies performed on patients with a life expectancy of fewer than 10 years aged 76 to 80 years was 30% in both sexes and increased with age-82% of men and 61% of women aged 81 to 85 years (71% total), and 100% of patients beyond the age of 85 years. Adverse events requiring hospitalizations were common at 10 days (13.58 per 1000) and increased with age, particularly among patients older than 85 years. The detection of advanced neoplasia varied from 5.4% among patients aged 76 to 80 years to 6.2% in those aged 81 to 85 years and 9.5% among patients older than 85 years (P = .02). Of the total population, 15 patients (0.2%) had invasive adenocarcinoma; among patients with a life expectancy of fewer than 10 years, 1 of 9 was treated, whereas 4 of 6 patients with a life expectancy of greater than or equal to 10 years were treated.

In this cross-sectional study with a nested cohort, most screening colonoscopies performed in patients older than 75 years were in patients with limited life expectancy and associated with increased risk of complications. Colorectal cancer was exceedingly rare.

For many cancers there are few well-established risk factors. Summary data from genome-wide association studies (GWAS) can be used in a Mendelian randomisation (MR) phenome-wide association study (PheWAS) to identify causal relationships. We performed a MR-PheWAS of breast, prostate, colorectal, lung, endometrial, oesophageal, renal, and ovarian cancers, comprising 378,142 cases and 485,715 controls. To derive a more comprehensive insight into disease aetiology we systematically mined the literature space for supporting evidence. We evaluated causal relationships for over 3,000 potential risk factors. In addition to identifying well-established risk factors (smoking, alcohol, obesity, lack of physical activity), we provide evidence for specific factors, including dietary intake, sex steroid hormones, plasma lipids and telomere length as determinants of cancer risk. We also implicate molecular factors including plasma levels of IL-18, LAG-3, IGF-1, CT-1, and PRDX1 as risk factors. Our analyses highlight the importance of risk factors that are common to many cancer types but also reveal aetiological differences. A number of the molecular factors we identify have the potential to be biomarkers. Our findings should aid public health prevention strategies to reduce cancer burden. We provide a R/Shiny app (https://mrcancer.shinyapps.io/mrcan/) to visualise findings.

Colorectal cancer is a common cause of cancer-related mortality in KSA with a rising incidence. Although adenomatous polyps are well-recognized as precursors of colorectal cancer, local data are scarce. Therefore, in this study, we aimed to evaluate the characteristics of adenomatous colon polyps in the Saudi population.

We retrospectively reviewed the electronic databases of all patients who underwent colonoscopy for any indication between January 2015 and December 2019 at a tertiary care hospital. This study included adult patients who were found to have colorectal polyps with identified histopathology reports. We collected clinical and pathological data, including patient age, sex, and histopathological polyp characteristics. A p-value <0.05 was considered significant for descriptive and analytical statistics.

A total of 184 patients with colorectal polyps with identified histopathology reports were included in the analysis. Of these, 130 (70.6%) patients were aged 50 years or older, and 135 (73.3%) were male. Among all polyps, 127 (69%) were adenomatous, 31 (16.8%) were hyperplastic, and 24 (13%) were inflammatory. For adenomatous polyps, 31 (24.4%) were observed in patients younger than 50 years, and high-grade dysplasia was observed in 23 (18%) polyps. Among patients with adenomatous polyps, the anatomical location was as follows: 27 (23%) in the cecum/ascending colon, 12 (9%) in the transverse colon, 45 (35%) in the descending/sigmoid colon, 25 (19%) in the rectum, and 18 (14%) at multiple sites. Age >50 years was significantly associated with adenomatous polyps (P = 0.03).

Approximately one-third of adenomatous polyps were detected proximal to the splenic flexure. Although adenomatous polyps were significantly associated with increasing age, 24% were observed in patients younger than 50 years of age. This finding supports the current recommendation to start screening at the age of 45.

Colorectal cancer (CRC) is the most common gastrointestinal malignancy and is generally thought to be caused by the transformation of colorectal polyps. It has been shown that early detection and removal of colorectal polyps may reduce the mortality and morbidity of colorectal cancer.

Based on the risk factors associated with colorectal polyps, an individualized clinical prediction model was built to predict and evaluate the possibility of developing colorectal polyp.

A case-control study was conducted. Clinical data were collected from 475 patients who underwent colonoscopy at the Third Hospital of Hebei Medical University from 2020 to 2021. All clinical data were then divided into training sets and validation sets by using R software (7:3). A multivariate logistic analysis was performed to identify the factors associated with colorectal polyps according to the training set, and a predictive nomogram was created by R software based on the multivariate analysis. The results were internally validated by receiver operating characteristic (ROC) curves, calibration curves, and externally validated by validation sets.

Multivariate logistic regression analysis showed that age (OR = 1.047, 95% CI = 1.029-1.065), history of cystic polyp (OR = 7.596, 95% CI = 0.976-59.129), and history of colorectal diverticulums (OR = 2.548, 95% CI = 1.209-5.366) were independent risk factors for colorectal polyps. History of constipation (OR = 0.457, 95% CI = 0.268-0.799) and fruit consumption (OR = 0.613, 95% CI 0.350-1.037) were protective factors for colorectal polyps. The nomogram demonstrated good accuracy for predicting colorectal polyps, with both C index and AUC being 0.747 (95% CI = 0.692-0.801). The calibration curves showed good agreement between the predicted risk by the nomogram and real outcomes. Both internal and external validation of the model showed good results.

In our study, the nomogram prediction model is reliable and accurate, which can help early clinical screening of patients with high-risk colorectal polyps, improve polyp detection rate, and reduce the incidence of colorectal cancer (CRC).

The gap in bowel cancer screening participation rates between the lowest socioeconomic position (SEP) groups and the highest in Australia is widening. This study estimates the long-term health impacts and healthcare costs at current colorectal cancer (CRC) screening participation rates by SEP in South Australia (SA).

A Markov microsimulation model for each socioeconomic quintile in SA estimated health outcomes over the lifetime of a population aged 50-74 years (total n = 513,000). The model simulated the development of CRC, considering participation rates in the National Bowel Cancer Screening Program and estimated numbers of cases of CRC, CRC deaths, adenomas detected, mean costs of screening and treatment, and quality adjusted life years. Screened status, stage of diagnosis and survival were obtained for patients diagnosed with CRC in 2006-2013 using data linked to the SA Cancer Registry.

We predict 10915 cases of CRC (95%CI: 8017─13812) in the lowest quintile (Q1), 17% more than the highest quintile (Q5) and 3265 CRC deaths (95%CI: 2120─4410) in Q1, 24% more than Q5. Average costs per person, were 29% higher in Q1 at $11997 ($8754─$15240) compared to Q5 $9281 ($6555─$12007). When substituting Q1 screening and diagnostic testing rates with Q5's, 17% more colonoscopies occur and adenomas and cancers detected increase by 102% in Q1.

Inequalities were evident in CRC cases and deaths, as well as adenomas and cancers that could be detected earlier. Implementing programs to increase screening uptake and follow-up tests for lower socioeconomic groups is critical to improve the health of these priority population groups.

Many screening programs for colorectal cancer (CRC) use the fecal immunochemical test (FIT) to triage individuals for colonoscopy. Although these programs reduce CRC incidence and CRC-related mortality, the detection of advanced precursor lesions (advanced adenomas and advanced serrated polyps) by FIT could be improved. As an alternative for FIT, the antibody-based multitargetFIT (mtFIT) has been proposed. The mtFIT measures three protein markers: hemoglobin, calprotectin, and serpin family F member 2. In a retrospective diagnostic accuracy study in a large colonoscopy-controlled series (n = 1284), mtFIT showed increased sensitivity for advanced neoplasia (AN), at equal specificity, compared to FIT (42.9% versus 37.3%; p = 0.025). This increase was mainly due to a higher sensitivity of mtFIT for advanced adenomas (37.8% versus 28.1% for FIT; p = 0.006). The present mtFIT study aims to prospectively validate these findings in the context of the Dutch national CRC screening program.

The mtFIT study is a cross-sectional intervention study with a paired design. Eligible subjects for the Dutch FIT-based national CRC screening program are invited to perform mtFIT in addition to FIT. Samples are collected at home, from the same bowel movement, and are shipped to a central laboratory by postal mail. If either one or both tests are positive, participants are referred for colonoscopy. Detailed colonoscopy and pathology data are centrally stored in a national screening database (ScreenIT; Topicus, Deventer, the Netherlands) that is managed by the screening organization, and will be retrieved for this study. We aim to determine the relative sensitivity for AN, comprising of CRC, advanced adenomas and advanced serrated polyps, of mtFIT compared to FIT at an equal positivity rate. Additionally, we will use the Adenoma and Serrated Pathway to Colorectal CAncer model to predict lifetime health effects and costs for programmatic mtFIT- versus FIT-based screening. The target sample size is 13,131 participants.

The outcome of this study will inform on the comparative clinical utility of mtFIT versus FIT in the Dutch national CRC screening program and is an important step forward in the development of a new non-invasive stool test for CRC screening.

Clinicaltrials.gov ; NCT05314309, registered April 6th 2022, first inclusions March 25th 2022 https://clinicaltrials.gov/ct2/results?cond=&term=NCT05314309&cntry=&state=&city=&dist =.

Cancer is one of the most common causes of death worldwide. A strong predisposition to cancer is generally only observed in colorectal cancer (5% of cases) and breast cancer (2% of cases). Colorectal cancer is the most common cancer with a strong genetic predisposition, but it includes dozens of various syndromes. This group includes familial adenomatous polyposis, attenuated familial adenomatous polyposis, MUTYH-associated polyposis, NTHL1-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, Lynch syndrome, and Muir-Torre syndrome. The common symptom of all these diseases is a very high risk of colorectal cancer, but depending on the condition, their course is different in terms of age and range of cancer occurrence. The rate of cancer development is determined by its conditioning genes, too. Hereditary predispositions to cancer of the intestine are a group of symptoms of heterogeneous diseases, and their proper diagnosis is crucial for the appropriate management of patients and their successful treatment. Mutations of specific genes cause strong colorectal cancer predispositions. Identifying mutations of predisposing genes will support proper diagnosis and application of appropriate screening programs to avoid malignant neoplasm.

Neoplasms of the small bowel are relatively rare, with less than 5% occurrence among other GI cases. Primary adenocarcinoma, an aggressive sub-type of small bowel cancers, usually presents with vague blood loss and abdominal pain symptoms, causing a delayed diagnosis at an advanced stage of the disease and a poor prognosis. The preferable treatment of choice is surgical resection with chemotherapy, which has shown to have survival benefits. Here we present a case of a 66-year-old male patient with persistent iron deficiency anemia requiring multiple blood transfusions and an unexplained weight loss. A series of diagnostic tests, including upper and lower GI endoscopy, Tc-99 RBC scintigraphy, barium follow-through, CT scans, bone marrow biopsy, esophagogastroduodenoscopy and colonoscopy were inconclusive. He was later diagnosed with a small bowel adenocarcinoma on exploratory laparotomy and surgically treated. Adjuvant chemotherapy was also started. Our case report highlights the course of SBA presenting in an unusual way which was challenging to diagnose with the standard investigations to help physicians/surgeons suspect it at an early stage in the future. This may save patients and help avoid delayed diagnosis or misdiagnosis, especially in patients with an unusual presentation like our patient who presented only with iron deficiency anemia.

Although the 9-minute mean withdrawal time (m-WT) is often reported to be associated with the optimal adenoma detection rate (ADR), no randomized trials of screening colonoscopy have confirmed the impact of a 9-minute m-WT on adenoma miss rate (AMR) and ADR.

A multicenter tandem trial was conducted in 11 centers. Seven hundred thirty-three asymptomatic participants were randomized to receive segmental tandem screening colonoscopy with a 9-minute withdrawal, followed by a 6-minute withdrawal (9-minute-first group, 9MF, n = 366) or vice versa (6-minute-first group, 6MF, n = 367). The primary outcome was the lesion-level AMR.

The intention-to-treat analysis revealed that 9MF significantly reduced the lesion-level (14.5% vs 36.6%, P < 0.001) and participant-level AMR (10.9% vs 25.9%, P < 0.001), advanced adenoma miss rate (AAMR, 5.3% vs 46.9%, P = 0.002), multiple adenomas miss rate (20.7% vs 56.5%, P = 0.01), and high-risk adenomas miss rate (14.6% vs 39.5%, P = 0.01) of 6MF without compromising detection efficiency ( P = 0.79). In addition, a lower false-negative rate for adenomas ( P = 0.002) and high-risk adenomas ( P < 0.05), and a lower rate of shortening surveillance schedule ( P < 0.001) were also found in 9MF, accompanying with an improved ADR in the 9-minute vs 6-minute m-WT (42.3% vs 33.5%, P = 0.02). The independent inverse association between m-WT and AMR remained significant even after adjusting ADR, and meanwhile, 9-minute m-WT was identified as an independent protector for AMR and AAMR.

In addition to increasing ADR, 9-minute m-WT also significantly reduces the AMR and AAMR of screening colonoscopy without compromising detection efficiency.

Owing to the heterogeneity of microbiota among individuals and populations, only Fusobacterium nucleatum and Bacteroides fragilis have been reported to be enriched in colorectal cancer (CRC) in multiple studies. Thus, the discovery of additional bacteria contributing to CRC development in various populations can be expected. We aimed to identify bacteria associated with the progression of colorectal adenoma to carcinoma and determine the contribution of these bacteria to malignant transformation in patients of Han Chinese origin.

Microbiota composition was determined through 16S rRNA V3-V4 amplicon sequencing of autologous adenocarcinomas, adenomatous polyps, and non-neoplastic colon tissue samples (referred to as "tri-part samples") in patients with CRC. Enriched taxa in adenocarcinoma tissues were identified through pairwise comparison. The abundance of candidate bacteria was quantified through genomic quantitative polymerase chain reaction (qPCR) in tissue samples from 116 patients. Associations of candidate bacteria with clinicopathological features and genomic and genetic alterations were evaluated through odds ratio tests. Additionally, the effects of candidate bacteria on CRC cell proliferation, migration, and invasion were evaluated through the co-culture of CRC cells with bacterial cells or with conditioned media from bacteria.

Prevotella intermedia was overrepresented in adenocarcinomas compared with paired adenomatous polyps. Furthermore, co-abundance of P. intermedia and F. nucleatum was observed in tumor tissues. More notably, the coexistence of these two bacteria in adenocarcinomas was associated with lymph node involvement and distant metastasis. These two bacteria also exerted additive effects on the enhancement of the migration and invasion abilities of CRC cells. Finally, conditioned media from P. intermedia promoted the migration and invasion of CRC cells.

This report is the first to demonstrate that P. intermedia is enriched in colorectal adenocarcinoma tissues and enhances the migration and invasion abilities of CRC cells. Moreover, P. intermedia and F. nucleatum exert additive effects on the malignant transformation of colorectal adenomas into carcinomas. These findings can be used to identify patients at a high risk of malignant transformation of colorectal adenomas or metastasis of CRC, and they can accordingly be provided optimal clinical management.

Within living organisms, stem cells respond to various cues, including to niche signals and growth factors. Niche signals originate from the stem cell's microenvironment and promote the undifferentiated state by preventing differentiation, allowing for stem cell self-renewal. On the other hand, growth factors promote stem cell growth and proliferation, while their sources comprise of a systemic input reflecting the animal's nutritional and metabolic status, and a localized, homeostatic feedback signal from the tissue that the stem cells serve. That homeostatic signal prevents unnecessary stem cell proliferation when the corresponding differentiated tissues already have optimal cell contents. Here, we recapitulate progresses made in our understanding of in vivo stem cell regulation, largely using simple models, and draw the conclusion that 2 types of stem cell deregulations can provoke the formation of benign tumors. Namely, constitutive niche signaling promotes the formation of undifferentiated "stem cell" tumors, while defective homeostatic signaling leads to the formation of differentiated tumors. Finally, we provide evidence that these general principles may be conserved in mammals and as such, may underlie benign tumor formation in humans, while benign tumors can evolve into cancer.

Recent studies have mapped key genetic changes in colorectal cancer (CRC) that impact important pathways contributing to the multistep models for CRC initiation and development. In parallel with genetic changes, normal and cancer tissues harbor epigenetic alterations impacting regulation of critical genes that have been shown to play profound roles in the tumor initiation. Cumulatively, these molecular changes are only loosely associated with heterogenous transcriptional programs, reflecting the heterogeneity in the various CRC molecular subtypes and the paths to CRC development. Studies from mapping molecular alterations in early CRC lesions and use of experimental models suggest that the intricate dependencies of various genetic and epigenetic hits shape the early development of CRC via different pathways and its manifestation into various CRC subtypes. We highlight the dependency of epigenetic and genetic changes in driving CRC development and discuss factors affecting epigenetic alterations over time and, by extension, risk for cancer.

After high-risk colorectal adenoma removal, colorectal cancer risk remains higher than that in the general population. Depending on polyp characteristics, a 3-month or 3-year follow-up colonoscopy is recommended, and clear follow-up instructions must be given to the patient. Our primary aim was to evaluate compliance with French follow-up recommendations. Second, we evaluated the impact of how the information was given and if patients actually underwent their control colonoscopy according to the instructions given.

We collected data from the Burgundy polyp population-based registry and medical records from the endoscopy centers of the area. Between June 30, 2014 and July 1, 2015, 405 patients were included in this study.

Written follow-up instructions were provided to 345 patients (85.2%), and 184 of them (53.3%) complied with guidelines. For 29.9% the interval to follow-up colonoscopy was longer than recommended, and for 6.4% the interval was shorter. Among the 303 patients who had clear follow-up instructions, 42.2% had their control colonoscopy and 83.6% respected the stipulated interval. Follow-up instructions were found in the colonoscopy report in at least 49% of cases.

Compliance with follow-up guidelines was poor: Inappropriate intervals were often longer than recommended. Patients with written follow-up instructions and those who underwent follow-up colonoscopy mostly followed these instructions. Ensuring compliance with guidelines and giving written instructions to patients should be primary goals to achieve effective follow-up. Gastroenterologist training should be improved in this way.

Colorectal cancer (CRC) is the third most prevalent type of cancer for incidence and second for mortality worldwide. Late diagnosis and inconvenient and expensive current diagnostic tools largely contribute to the progress of the disease. The use of chemotherapy in the management of CRC significantly reduces tumor growth, metastasis, and morbidity rates. However, poor solubility, low cellular uptake, nonspecific distribution, multiple drug resistance and unwanted adverse effects are still among the major drawbacks of chemotherapy that limit its clinical significance in the treatment of CRC. Owing to their remarkable advantages over conventional therapies, the use of nanotechnology-based delivery systems especially polymeric nanocarriers (PNCs) has revolutionized many fields including disease diagnosis and drug delivery.

In this review, we shed the light on the current status of using PNCs in the diagnosis and treatment of CRC with a special focus on targeting strategies, surface modifications and safety concerns for different types of PNCs in colonic cancer delivery.

The review explores the current progress on the use of PNCs in the diagnosis and treatment of CRC with a special focus on the role of PNCs in improvement of cellular uptake, drug targeting and co-delivery of chemotherapeutic agents. Possible toxicity and biocompatibility issues related to the use of PNCs and imitations and future recommendation for the use of those smart carriers in the diagnosis and treatment of CRC are also discussed.