To evaluate the prognostic significance of the albumin-to-alkaline phosphatase ratio (AAPR) and the Controlling Nutritional Status (CONUT) score in rectal cancer (RC) patients receiving XELOX-based chemotherapy, and to develop a nomogram for predicting recurrence risk.

This retrospective study included 389 RC patients treated at the First Affiliated Hospital of Chongqing Medical University, along with an independent validation cohort of 120 patients. Clinical variables, including AAPR and CONUT were analyzed using Cox regression and cumulative incidence function curves. A nomogram was constructed and validated using calibration plots and time-dependent receiver operating characteristic (ROC) curves.

Both AAPR (HR = 0.073, P<0.001) and CONUT score (HR = 1.497, P<0.001) were identified as independent predictors of recurrence. Additional factors significantly associated with increased recurrence risk included TNM stage III, tumor size ≥5 cm, vascular invasion, and carcinoembryonic antigen (CEA) level ≥5 ng/ml. The nomogram demonstrated strong predictive performance with a C-index of 0.860 in the training cohort, and 0.835 in the validation cohort. Calibration plots showed excellent agreement between predicted and observed recurrence probabilities.

AAPR and CONUT score are independent prognostic indicators for recurrence in RC patients treated with XELOX-based chemotherapy. The proposed nomogram, incorporating these variables, provides a reliable tool for individualized risk prediction and may support personalized treatment decision-making.

In recent years, new therapeutic approaches have emerged in addition to classical neoadjuvant (chemo)radiotherapy for the treatment of locally advanced rectal cancer (LARC): total neoadjuvant treatment, non-operative management, and radiotherapy-free strategy. While the introduction of these approaches in a relatively short timeframe has quickly increased our therapeutic armamentarium, on the other hand it has complicated the decision-making process regarding the choice of the most appropriate treatment strategy for each patient with LARC. Therefore, a tool to interpret the evidence from clinical trials and to translate them into daily practice is highly demanded. In the present review, we address how these new developments are changing the multimodal treatment of LARC and offer an algorithm to integrate them into clinical practice.

With the results of several recently published clinical trials, this guideline focused update provides evidence-based recommendations for the indications and dose-fractionation regimens for neoadjuvant radiation therapy (RT), optimal sequencing of RT and systemic therapy in the context of total neoadjuvant therapy (TNT), and considerations for selective omission of RT and surgery for rectal cancer.

The American Society for Radiation Oncology convened a multidisciplinary task force to update 3 key questions that focused on the role of RT for patients with operable rectal cancer. The key questions addressed (1) indications for neoadjuvant RT, (2) selection of neoadjuvant regimens, and (3) indications for consideration of a nonoperative management (NOM) or local excision approach after definitive/preoperative chemoradiation. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for quality of evidence grading and strength of recommendation.

For patients with stage II-III rectal cancer, neoadjuvant RT was strongly recommended; however, among patients deemed at lower risk of locoregional recurrence, consideration of omission of neoadjuvant RT was conditionally recommended in favor of neoadjuvant chemotherapy with a favorable treatment response or upfront surgery. For patients with T3-T4 and node-positive rectal cancer undergoing neoadjuvant RT, a TNT approach was strongly recommended. Among patients with higher risk of locoregional recurrence, TNT with chemotherapy before or after long-course chemoradiation was strongly recommended, whereas TNT with short-course RT followed by chemotherapy was conditionally recommended. For patients with rectal cancer for whom NOM is a priority, concurrent chemoradiation followed by consolidation chemotherapy was strongly recommended. Selection of RT dose-fractionation regimen, sequencing of therapies, and consideration of NOM should be determined by multidisciplinary consensus and based on disease extent, disease location, patient preferences, and quality of life considerations.

The task force proposed recommendations to inform best clinical practices on the use of RT for rectal cancer with strong emphasis on multidisciplinary care. Future studies should focus on further addressing optimal treatment regimens to allow for more personalized recommendations based on individual risk stratification and patient priorities regarding quality of life.

Colorectal cancer (CRC) is the second most prevalent cause of cancer-related death and the third most common cancer globally. Early-stage rectal cancer is defined by lesions confined to the bowel wall, without extension beyond the submucosa in T1 or the muscularis propria in T2, with no indication of lymph node involvement or distant metastasis. The gold standard for managing rectal cancer is total mesorectal excision (TME); however, it is linked to considerable morbidities and impaired quality of life. There is a growing interest in local resection and non-operative treatment of early RC for organ preservation. Local resection options include three types of transanal endoscopic surgery (TES): transanal endoscopic microsurgery (TEM), transanal endoscopic operations (TEO), and transanal minimally invasive surgery (TAMIS), while endoscopic resection includes endoscopic mucosal resection (EMR), underwater endoscopic mucosal resection (UEMR), and endoscopic submucosal dissection (ESD). Although the oncological outcome of local resection of early rectal cancer is debated in the current literature, some studies have shown comparable outcomes with radical surgery in selected patients. The use of adjuvant and neoadjuvant chemoradiotherapy in early rectal cancer management is also controversial in the literature, but a number of studies have reported promising outcomes. This review focuses on the available literature regarding diagnosis, staging, and management strategies of early rectal cancer and provides possible recommendations.

Organ preservation (OP) strategies are gaining interest in improving the quality of life in the management of rectal cancer, particularly for tumors located in the distal or middle rectum. The optimal OP protocol is still not standardized and relies on randomized trials. This review summarizes past and ongoing studies on OP protocols for adenocarcinoma of the distal and middle rectum.

We searched for articles and abstracts on randomized clinical trials investigating OP approaches for rectal cancer, including data presented at the LUCARRE Congress held in Nice on November 25, 2023, covering ongoing and recently published trials on rectal preservation.

Our review's findings are presented in four tables: the first evaluates key trials with overall survival (OS) as the primary endpoint; the second provides an overview of past Phase III trials; the third reviews Phase II/III trials that specifically focus on local excisions (LE); and finally, the fourth summarizes ongoing trials. Each table is accompanied by detailed comments elucidating the significance and implications of the presented data, alongside a review of current guidelines.

We highlight the growing interest in OP strategies for rectal cancer management to enhance patients' quality of life. Despite the lack of international consensus on the optimal OP protocol, past and ongoing randomized trials provide valuable findings into the evolving management strategies of rectal cancer treatment. The presented data supports the role of randomized phase III trials to provide evidence for a change in clinical practice.

Local excision (LE) for T1 rectal cancer may be recommended in those with low-risk disease, while resection is typically recommended in those with a high risk of luminal recurrence or lymph node metastasis. The aim of this work was to compare survival between resection and LE.

This was a population-based retrospective cohort study set in the Canadian province of Ontario. Patients were individuals with T1Nx rectal cancer between 2010 and 2014 and demographics, disease characteristics, treatments and outcomes were determined using linked administrative databases. This study does not include clinical information regarding individual patient treatment decisions. The main outcome measure was overall survival (OS).

A total of 719 patients were identified, including 359 with upfront resection, 113 with LE and immediate resection (<90 days) and 247 with LE with definitive intent. The majority of LEs were performed via colonoscopy. Piecemeal excision (42% vs. 49%, p = 0.28) and positive margin (50% vs. 77%, p < 0.01) rates were high in both LE groups, with the highest rate in those with immediate resection. The prevalence of poor differentiation (<5%, p = 0.70) and lymphovascular invasion (LVI) (14%, p = 0.80) was similar across groups. In those with LE with definitive intent, 21% ultimately underwent resection (median 150 days, interquartile range 114-181 days) and 4% received radiation. There was no difference in 5-year OS between groups (resection 83.2% vs. LE and immediate resection 82.3% vs. definitive LE 83.3%; p = 0.33). Adjusted analyses demonstrated no association between approach and survival [definitive intent LE hazard ratio (HR) 0.97 (95% CI 0.70-1.35), LE and immediate resection HR 0.97 (95% CI 0.60-1.45), upfront resection HR 1 (Ref); p = 0.98]. Differentiation, piecemeal excisions and LVI were not associated with OS in the LE groups.

There were no observed differences in survival between those who underwent resection, LE and immediate resection and definitive intent LE. Although, these are observational data, they call into question the reflexive decision to offer radical resection for those with suspected T1 rectal cancer.

In contrast to significant advances in organ preservation in locally advanced rectal cancer, the contemporary management of early-stage rectal cancer, including the frequency of abdominoperineal resections, remains largely unexplored in the United States. Therefore, we assessed the utilization of neoadjuvant therapy and oncological resections in early-stage rectal cancer patients.

This is a retrospective cohort study of patients with cT1-T3N0 rectal cancer who underwent proctectomies between 2016 and 2022 in the National Surgical Quality Improvement Project proctectomy files. Multivariable logistic regression was used to identify factors associated with abdominoperineal resections and Kendall's tau statistics to evaluate clinical-pathological staging agreement.

In all, 3078 patients (29.6% cT1-2N0, 70.4% cT3N0) were included with 55.3% of tumours <5 cm from the anal verge. Overall, 58.2% received neoadjuvant therapy within 3 months of surgery (30.6% for cT1-T2N0 vs. 69.8% for cT3N0, P < 0.001), and 58.6% underwent abdominoperineal resection (55.5% for cT1-T2N0 vs. 59.9% for cT3N0, P = 0.058). The adjusted odds of undergoing abdominoperineal resection were associated with increasing age (OR 1.4 per every 10-year increase; 95% CI 1.2-1.5), cT3N0 tumours (OR 1.7; 95% CI 1.1-2.7) and tumour location <5 cm from the anal verge (OR 10.6; 95% CI 7.7-14.7). There was a weak clinical-pathological T staging correlation (Kendal tau coefficient 0.25; 95% CI 0.20-0.29).

In this large cohort of patients with early-stage rectal cancer with high rates of neoadjuvant therapy, over half of patients underwent abdominoperineal resection and one in five had a pathological complete response. These findings underscore opportunities for organ preservation in early-stage rectal cancer, suggesting that treatments typically reserved for locally advanced disease may extend to early stages with the completion of ongoing clinical trials.

For patients with rectal cancer, the standard approach of chemotherapy, radiation therapy, and surgery (trimodality therapy) is associated with significant long-term toxicity and/or colostomy for most patients. Patient options focused on quality of life (QOL) have dramatically improved, but there remains limited guidance regarding comparative effectiveness. This systematic review and associated guidelines evaluate how various treatment strategies compare to each other in terms of oncologic outcomes and QOL. Cochrane and Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) methodology were used to search for prospective and retrospective trials and meta-analyses of adequate quality within the Ovid Medline database between January 1, 2012, and June 15, 2023. These studies informed the expert panel, which rated the appropriateness of various treatments in 6 clinical scenarios through a well-established consensus methodology (modified Delphi). The search process yielded 197 articles that advised voting. Increasing data have shown that nonoperative management (NOM) and primary surgery result in QOL benefits noted over trimodality therapy without detriment to oncologic outcomes. For patients with rectal cancer for whom total mesorectal excision would result in permanent colostomy or inadequate bowel continence, NOM was strongly recommended as usually appropriate. Restaging with tumor response assessment approximately 8 to 12 weeks after completion of radiation therapy/chemoradiation therapy was deemed a necessary component of NOM. The panel recommended active surveillance in the setting of a near-complete or complete response. In the setting of NOM, 54 to 56 Gy in 27 to 31 fractions concurrent with chemotherapy and followed by consolidation chemotherapy was recommended. The panel strongly recommends primary surgery as usually appropriate for a T3N0 high rectal tumor for which low anterior resection and adequate bowel function is possible, with adjuvant chemotherapy considered if N+. Recent data support NOM and primary surgery as important options that should be offered to eligible patients. Considering the complexity of multidisciplinary management, patients should be discussed in a multidisciplinary setting, and therapy should be tailored to individual patient goals/values.

Postoperative bowel dysfunction following restorative proctectomy, commonly referred to as Low Anterior Resection Syndrome (LARS), is a common long term sequela of rectal cancer treatment. While many of the established risk factors for LARS are non-modifiable, others may be well within the surgeon's control. Several pre-, intra-, and postoperative decisions may have a significant impact on postoperative bowel function. Some of these factors include the extent of surgical resection, surgical approach, choice of anastomotic reconstruction, and use of fecal diversion. This review article summarizes the available evidence regarding how surgical decision-making can affect postoperative bowel function.

T1 colorectal cancer (CRC), defined by tumor invasion confined to the submucosa, has historically been managed by surgery. Improved understanding of recurrence and lymph node metastases risk, coupled with advances in endoscopic resection techniques, have led to an increasing capacity for organ-sparing local excision. Minimally invasive management of T1 CRC begins with optical evaluation of the lesion to diagnose invasive disease and quantify depth of invasion, which informs therapeutic decision making. Modality selection between various available endoscopic resection techniques depends upon lesion characteristics, technique risk-benefit profiles, and location-specific implications. Following endoscopic resection, established histopathology features determine the risk of recurrence and subsequent management including surveillance or adjuvant surgical excision. The management of non-operative candidates deviates from conventional recommendations with emerging treatment strategies in select populations.

Colorectal cancer (CRC) poses a significant global health challenge. Notably, the risk of CRC escalates with age, with the majority of cases occurring in those over the age of 65. Despite recent progress in tailoring treatments for early and advanced CRC, there is a lack of prospective data to guide the management of older patients, who are frequently underrepresented in clinical trials. This article reviews the contemporary landscape of managing older individuals with CRC, highlighting recent advancements and persisting challenges. The role of comprehensive geriatric assessment is explored. Opportunities for treatment escalation/de-escalation, with consideration of the older adult's fitness level. are reviewed in the neoadjuvant, surgical, adjuvant, and metastatic settings of colon and rectal cancers. Immunotherapy is shown to be an effective treatment option in older adults who have CRC with microsatellite instability. Promising new technologies such as circulating tumor DNA and recent phase III trials adding later-line systemic therapy options are discussed. Clinical recommendations based on the data available are summarized. We conclude that deliberate efforts to include older individuals in future colorectal cancer trials are essential to better guide the management of these patients in this rapidly evolving field.

A rise in the incidence of early rectal cancer consequent to bowel-screening programs around the world and an increase in the incidence in young adults has led to a growing interest in organ-sparing treatment options. The rectum, being the most distal portion of the large intestine, is a fertile ground for local excision techniques performed with endoscopic or surgical techniques. Moreover, the advancement in endoscopic optical evaluation and the better definition of imaging techniques allow for a more precise local staging of early rectal cancer. Although the local treatment of early rectal cancer seems promising, in clinical practice, a significant number of patients who could benefit from local excision techniques undergo total mesorectal excision (TME) as the first approach. All relevant prospective clinical trials were identified through a computer-assisted search of the PubMed, EMBASE, and Medline databases until January 2024. This review is dedicated to endoscopic and surgical local excision in the treatment of early rectal cancer and highlights its possible role in current and future clinical practice, taking into account surgical completion techniques and chemoradiotherapy.

Staging and treatment of rectal cancer have evolved over several decades with considerably fewer locoregional recurrences but no marked improved survival since systemic recurrence risks remain virtually unchanged. This development will briefly be summarised followed by a thorough discussion of two recent developments.

A systematic approach towards the literature is aimed at focusing on organ preservation and the delivery of all non-surgical treatments prior to surgery or total neoadjuvant treatment (TNT).

Organ preservation, that is to defer surgery if the tumour happens to disappear completely after any pre-treatment given to locally advanced tumours to decrease recurrence risks has increased in popularity and is, if not universally, widely accepted. To give neo-adjuvant treatment to intentionally obtain a clinically complete remission to avoid surgery is practised in some environments but is mostly still experimental. TNT, that is to provide both radiotherapy and chemotherapy aimed at killing microscopic disease in the pelvis or elsewhere has been subject to several trials. Collectively, they show that the chance of achieving a complete response, pathologically or clinically, has approximately doubled, increasing the chance for organ preservation, and the risk of distant metastasis has decreased at least in some trials. The best schedule remains to be established.

To obtain substantial progress and also improve survival, the systemic treatments need to be improved even if preoperative delivery is more effective and better tolerated than postoperative. The locoregional treatment may be further optimised through better risk prediction.

Nonoperative treatment of rectal cancer is gaining popularity. Several trials recently demonstrated advantages in disease-free survival with total neoadjuvant treatment (TNT) with the addition of the watch and wait (WW) strategy for locally advanced rectal cancer. On longer follow-up, an unexpected increased risk in local recurrence in the TNT group at the RAPIDO trial suggested early surgery for nonresponding tumours. The WW option is globally accepted for a complete clinical response; however, a high rate of regrowth was found in a registry with an increased risk of distant metastases, questioning the deleterious effect of deferral of surgery in this group. The short- and long-term toxic effects of neoadjuvant treatment are costs to consider in the National Comprehensive Cancer Network guidelines compared with the European Society for Medical Oncology guidelines, which favour surgery alone if good mesorectal resection is assured with increasing surgical proficiency adjusted to the precise anatomical location.

The management of early-stage rectal cancer in clinical practice is controversial. The aim of this network meta-analysis was to compare oncological and postoperative outcomes for T1T2N0M0 rectal cancers managed with local excision in comparison to conventional radical resection.

A systematic review of Medline, Embase and Cochrane electronic databases was performed. Relevant studies were selected using PRISMA guidelines. The primary outcomes measured were 5-year local recurrence and overall survival. Secondary outcomes included rates of postoperative complication, 30-day mortality, positive margin and permanent stoma formation.

Three randomized controlled trials and 27 observational studies contributed 8570 patients for analysis. Radical resection was associated with reduced 5-year local recurrence in comparison to local excision. This was statistically significant in comparison to trans-anal local excision (odds ratio (OR) 0.23; 95% confidence interval 0.16-0.30) and favourable in comparison to endoscopic techniques (OR 0.40; 95% confidence interval 0.13-1.23) although this did not reach clinical significance. Positive margin rates were lowest for radical resection. However, 30-day mortality rates, perioperative complications and permanent stoma rates all favoured local excision with no statistically significant difference between endoscopic and trans-anal techniques.

Radical resection of early rectal cancer is associated with the lowest 5-year local recurrence rates and the lowest rate of positive margins. However, this must be balanced with its higher 30-day mortality and complication rates as well as the increased risk of permanent stoma. The emerging potential role of neoadjuvant therapy prior to local resection, and the heterogeneity of its use, as an alternative treatment for early rectal cancer further complicates the treatment paradigm and adds to controversy in this field.

The optimal management of locally advanced rectal cancer is rapidly evolving. The National Cancer Institute Rectal-Anal Task Force convened an expert panel to develop consensus on the design of future clinical trials of patients with rectal cancer. A series of 82 questions and subquestions, which addressed radiation and neoadjuvant therapy, patient perceptions, rectal cancer populations of special interest, and unique design elements, were subject to iterative review using a Delphi analytical approach to define areas of consensus and those in which consensus is not established. The task force achieved consensus on several areas, including the following: 1) the use of total neoadjuvant therapy with long-course radiation therapy either before or after chemotherapy, as well as short-course radiation therapy followed by chemotherapy, as the control arm of clinical trials; 2) the need for greater emphasis on patient involvement in treatment choices within the context of trial design; 3) efforts to identify those patients likely, or unlikely, to benefit from nonoperative management or minimally invasive surgery; 4) investigation of the utility of circulating tumor DNA measurements for tailoring treatment and surveillance; and 5) the need for identification of appropriate end points and recognition of challenges of data management for patients who enter nonoperative management trial arms. Substantial agreement was reached on priorities affecting the design of future clinical trials in patients with locally advanced rectal cancer.

Total mesorectal excision (TME) is the standard-of-care in early, clinical stage (cT2-3 N0 M0) rectal cancer. Local excision (LE) may be an alternative after adequate response to neoadjuvant therapy (NAT), with either long-course chemoradiotherapy (nCRT) or short-course radiotherapy (SCRT), as a means of preserving the rectum and potentially obviating the morbidity of TME.

A systematic review was performed according to PRISMA guidelines for studies that randomly assigned patients with cT2-3 N0 M0 rectal cancer to either NAT + LE or TME that reported radiologic, oncologic, surgical, and morbidity outcomes.

A total of 4 RCTs comprise 462 patients (232 patients receiving NAT + LE; nCRT n = 205; SCRT n = 27) and 230 undergoing TME, respectively. NAT compliance was 98.86%. The rate of early completion TME in the NAT + LE group was 22.3%, while the proportion of patients achieving durable organ preservation was 75.4% at mean follow-up of 5.6 years. There was no difference in disease-free survival (DFS) (HR [hazard ratio] 1.19; 95% CI 0.95, 1.49; p = 0.13) or overall survival (OS) (HR 0.94; 95% CI 0.72, 1.23; p = 0.63]) according to the assigned treatment arm. The local recurrence rate (LRR) (HR 1.22; 95% CI 0.5-3.02; p = 0.66) and distant metastases (HR 0.92; 95% CI 0.45, 1.90; p = 0.82) were also comparable between the groups. There was a significant reduction in major (OR 0.45; 95% CI 0.21, 0.95; p = 0.04) and minor morbidity (OR 0.45; 95% CI 0.24, 0.85; p = 0.01) for patients undergoing NAT + LE. Overall stoma formation was decreased in the NAT + LE group (OR 0.03; 95% CI 0.0, 0.23; p ≤ 0.00001).

NAT + LE reduces adverse effects of TME, without any compromise in oncological outcomes, and the potential for an organ preserving strategy should be discussed with patients with T2-3N0 rectal cancers prior to treatment.

Total neoadjuvant treatment (TNT) is becoming standard in patients with locally advanced rectal carcinoma (LARC). Preoperative chemoradiotherapy (CRT) has proven side effects on bowel and genitourinary function. An early tumoral response to induction chemotherapy demonstrates its high prognostic value. Tailored management could be used as an alternative to systematic CRT. The GRECCAR 14 trial will attempt to personalize treatment strategy according to the patient's early tumour response to intensive chemotherapy with the aim of achieving the best toxicity-efficiency ratio.

GRECCAR 14 is a multicentric, randomized, two-arm, phase II-III noninferiority trial. Patients with mid or low LARC with a predictive circumferential resection margin ≤2 mm or T3c-d stage with extramural venous invasion will be included. Evaluation of the tumoral response will be performed after six courses of high-dose FOLFIRINOX chemotherapy. Good responders (GRs) will be defined by a 60% decrease in tumoral volume on magnetic resonance imaging. Patients will be randomized to CRT before surgery. The primary endpoints will be R0 resection for phase II and the 3-year disease-free survival (DFS) for phase III.

Tailored management of LARC is becoming an exciting challenge for the modality of neoadjuvant treatment and for the type of surgery or its omission. Neoadjuvant FOLFIRINOX has established efficacy, with a significant increase in the 3-year DFS. Better control of systemic disease must be accompanied by the same locoregional control, with the lowest morbidity. Our previous GRECCAR 4 trial demonstrated the high value of the early tumoral response after induction chemotherapy and the long-term safety of tailored management for GRs.

If GRECCAR 14 demonstrates the ability to tailor TNT for LARC, this could lead to changes in clinical practice.

Total neoadjuvant therapy (TNT), which includes chemotherapy and radiation prior to surgical resection, has been recently accepted as the new standard of care for patients with locally advanced low and mid rectal cancers. Multiple clinical trials have evaluated this approach in the last several decades and demonstrated improvement in, local control and reduced risk of recurrence. In addition, in the course of these investigations, it has been shown that between a third and a half of patients experience a clinical complete response (cCR) after being treated with the TNT approach, leading to the development of new organ preservation protocol, now known as watch-and-wait (W&W). On this protocol, cCR patients are not referred for surgery after total neoadjuvant treatment. Instead, they remain on close surveillance and, thus, avoid potential complications associated with surgical resection. Multiple clinical trials are ongoing, investigating the long-term outcomes of these new approaches and the development of less toxic and more effective TNT regimens for LARC. Improvements in technology and rectal MRI protocols position radiologists as vital members of multidisciplinary rectal cancer management teams. Rectal MRI has become a critical tool for rectal cancer initial staging, treatment response assessment, and surveillance on W&W protocols. In this review, we summarize the findings of the pivotal clinical trials that contributed to establishing the current treatment paradigms in locally advanced rectal cancer (LARC) management, with the intention of helping radiologists play more effective roles in their multidisciplinary teams.

We performed this study to identify predictive factors for lymph node metastasis (LNM) and analyze the impact of LNM on the prognosis of patients with T1-2 colorectal cancer (CRC), with the intention of providing guidance for the treatment.

The Surveillance Epidemiology and End Result database was used to identify 20,492 patients diagnosed with T1-2 stage CRC between 2010 and 2019, who underwent surgery and lymph node evaluation and had complete prognostic information. Clinicopathological data of patients with T1-2 stage colorectal cancer treated with surgery at Peking University People's Hospital from 2017 to 2021 with complete clinical information were retrieved. We identify and confirm the risk factors for positive lymph node involvement, and the results of follow-up were analyzed.

Age, preoperative carcinoembryonic antigen (CEA) level, perineural invasion, and primary tumor site were independent risk factors for LNM in T1-2 CRC based on the analysis of the SEER database, while tumor size and histology of mucinous carcinoma were also independent risk factors in T1 CRC. We then make the nomogram model for predicting LNM risk and showed an acceptable consistency and calibration capability. Survival analysis showed that LNM was an independent prognostic indicator of 5-year disease-specific survival (P = 0.013) and disease-free survival (P < 0.001) in patients with T1 and T2 CRC.

Age, CEA level and primary tumor site should be taken into consideration before making the surgical decision in T1-2 CRC patients. The tumor size and histology of mucinous carcinoma also need to be thought about in T1 CRC. Conventional imaging tests do not appear to provide a precise assessment for this issue.

In the treatment of early-stage rectal cancer, a growing number of studies have shown that transanal endoscopic microsurgery is one of the alternatives to radical surgery adhering to total mesorectal excision that can reduce the incidence of adverse events without compromising treatment outcomes. The purpose of this meta-analysis is to compare the safety and treatment effect of transanal endoscopic microsurgery and radical surgery adhering to total mesorectal excision to provide a basis for clinical treatment selections.

We searched the literatures of four major databases, PubMed, Embase, Web of science, and Cochrane Library, without limitation of time. The literatures included randomized controlled studies and cohort studies comparing two surgical procedures of transanal endoscopic microsurgery and radical surgery adhering to total mesorectal excision. Treatment effectiveness and safety results of transanal endoscopic microsurgery and radical surgery were extracted from the included literatures and statistically analyzed using RevMan5.4 and stata17.

Ultimately, 13 papers were included in the study including 5 randomized controlled studies and 8 cohort studies. The results of the meta-analysis showed that the treatment effect and safety of both transanal endoscopic microsurgery and radical surgery in distant metastasis (RR, 0.59 (0.34, 1.02), P > 0.05), overall recurrence (RR, 1.49 (0.96, 2.31), P > 0.05), disease-specific-survival (RR, 0.74 (0.09, 1.57), P > 0.05), dehiscence of the sutureline or anastomosis leakage (RR, 0.57 (0.30, 1.06), P > 0.05), postoperative bleeding (RR, 0.47 (0.22, 0.99), P > 0.05), and pneumonia (RR, 0.37, (0.10, 1.40), P > 0.05) were not significantly different. However, they differ significantly in perioperative mortality (RR, 0.26 (0.07, 0.93, P < 0.05)), local recurrence (RR, 2.51 (1.53, 4.21), P < 0.05),_overall survival_ (RR, 0.88 (0.74, 1.00), P < 0.05), disease-free-survival (RR, 1.08 (0.97, 1.19), P < 0.05), temporary stoma (RR, 0.05 (0.01, 0.20), P < 0.05), permanent stoma (RR, 0.16 (0.08, 0.33), P < 0.05), postoperative complications (RR, 0.35 (0.21, 0.59), P < 0.05), rectal pain (RR, 1.47 (1.11, 1.95), P < 0.05), operation time (RR, -97.14 (-115.81, -78.47), P < 0.05), blood loss (RR, -315.52 (-472.47, -158.57), P < 0.05), and time of hospitalization (RR, -8.82 (-10.38, -7.26), P < 0.05).

Transanal endoscopic microsurgery seems to be one of the alternatives to radical surgery for early-stage rectal cancer, but more high-quality clinical studies are needed to provide a reliable basis.

The treatment of rectal cancer has evolved with the advancement of surgical techniques. Less invasive approaches are becoming more accepted as the primary treatment method.

Such methods as transanal excision, transanal endoscopic microsurgery, and transanal minimally invasive surgery can reduce morbidity and mortality rates. However, not all patients are suitable candidates for these procedures, and proper diagnostics are necessary to establish indications. Compared to total mesorectal excision, transanal excision techniques have been shown to have fewer complications and comorbidities while still being able to remove cancerous tissue entirely. Transanal excision is the simplest method, where the operator removes visible rectal lesions. The basic principle of transanal endoscopic microsurgery is to dilate the rectum mechanically and by air insufflation and then use special surgical instruments to remove suspicious lesions under the vision of a telescope. Transanal minimally invasive surgery combines transanal endoscopic microsurgery and single-incision laparoscopic surgery, making the hard-to-reach proximal rectum accessible to classic laparoscopic instruments.

Local excision techniques, when used as a monotherapy for treating patients with rectal cancer, have established themselves as a curative and less radical treatment for strictly selected patients with early rectal carcinoma, leading to improved quality of life. When combined with other modalities such as neoadjuvant chemoradiotherapy, total neoadjuvant therapy, and immunotherapy, transanal surgery can be offered to patients with locally advanced rectal cancer as part of the organ preservation strategy. This review will discuss the patient selection and technical aspects of transanal surgery, showcasing its current role in treating rectal carcinoma.