In the last decade, the role of radiotherapy in rectal cancer has changed significantly with the introduction of total neoadjuvant therapy (TNT) and nonoperative management (NOM). For the setting of irradiation field in rectal cancer, the pararectal, lateral lymph nodes, and those along the inferior mesenteric artery (IMA) are most important. In total mesorectal excision (TME), the root of the IMA is dissected. In the atlas of pelvic irradiation for rectal cancer, the setting of the upper margin of the mesorectum varies from atlas to atlas, and no atlas sets the upper margin of the mesorectum to the root of the IMA. In particular, there is no consensus on the definition of anatomical boundaries regarding the lymph nodes along the superior rectal artery (SRA). The upper margin of the irradiation field in clinical trials of preoperative radiotherapy and TNT is generally set at the level of the internal and external iliac artery branches, L5/S1, or S2/S3. However, it is not necessary to include the entire mesorectum to the root of the IMA in patients undergoing preoperative radiotherapy plus TME. Conversely, for patients receiving NOM, the irradiation field may have to include the mesorectum to the IMA root, though the incidence of lymph node metastasis and gastrointestinal adverse events merits consideration. It is increasingly important to determine the extent of clinical target volume around the SRA region and the setting of the upper margin of the irradiation field after formulating the treatment policy together with the surgeons and medical oncologists.

Rectal cancer accounts for approximately 40% of colorectal cancer cases, and lateral pelvic lymph node (LPLN) metastasis in rectal cancer significantly increases the local recurrence rate. Despite its clinical significance, studies on the molecular biology of LPLN metastasis are relatively scarce. In this study, we aimed to elucidate the underlying mechanisms by identifying hub regulatory genes in LPLN tissues and analyzing differentially expressed genes shared between tumor and pericarcinomatous tissues within our clinical cohort. To investigate the biological functions of these hub regulatory genes, we performed GSEA, GO, and KEGG pathway analyses on mRNA-Seq data. Among the identified hub genes, KLF12 emerged as a pivotal regulatory gene in rectal cancer. We further explored its clinical relevance and biological function. Our findings, validated using public databases, clinical cohort data, and immunohistochemistry (IHC), identified KLF12 as a specific marker for LPLN. Additionally, KLF12 expression exhibited a strong correlation with disease-free survival (DFS). According to clinical data, significant differences in KLF12 expression exist between groups based on factors such as age, gender, tumor location, pathological N stage, and postoperative tumor residue. Both treatment outcomes (DFS) and receiver operating characteristic curves (AUCs) were significantly associated with KLF12 expression. Furthermore, KLF12 demonstrated a strong association with immune cell infiltration, immune checkpoint expression, and immunophenoscore (IPS), indicating its potential regulatory role in immunotherapy. Functional molecular experiments revealed that KLF12 overexpression inhibited the proliferation, migration, and invasion of SW620 cells. In conclusion, leveraging mRNA-Seq data, TCGA database analysis, immune infiltration data, and biological function assessments, we confirmed that KLF12 could serve as an effective predictive marker and potential therapeutic target for LPLN metastasis. These findings suggest that KLF12 may be instrumental in assessing predictive risk and identifying novel therapeutic targets for patients with rectal cancer.

Distal, locally advanced rectal cancer might spread to lateral lymph nodes (LLNs), posing a risk of lateral local recurrence (LLR). This study evaluated quality-controlled implementation of lateral lymph node dissection (LLND) in the Netherlands.

This retrospective multicenter cohort study included consecutively treated rectal cancer patients who underwent neoadjuvant therapy, total mesorectal excision (TME) surgery, and nerve-sparing minimally invasive LLND by trained surgeons across 10 Dutch hospitals. Training involved cadaver sessions, monthly video meetings, and proctoring. Outcome measures included intra- and postoperative complications, urogenital dysfunction and 18-month LLR, local recurrence (LR), and disease-free survival (DFS).

The study comprised 41 patients (median follow-up period, 16 months; interquartile range, IQR, 8-21 months) with advanced tumors (27% cT4, 49% cN2, 7% cM1), and a mean LLN size of 11 mm on primary-staging MRI. Abdominoperineal resection was performed for 29 patients (70%). A beyond TME procedure was performed for 11 patients (28%). The median blood-loss was 250 ml (IQR, 100-400 ml), with obturator nerve injury reported in one patient. Malignant LLNs were found in 41% of the LLND specimens. Complications occurred for 22 patients (54%), 21% (9/41) of which were grade 3 or higher. Nine patients (22%, four of whom underwent beyond TME surgery) had a Foley or intermittent urinary catheter at the end of the follow-up period. Sexual dysfunction of three patients was reported. No ipsilateral LLRs occurred. The 18-month LR rate was 14%, and the DFS was 55%.

Minimally invasive nerve-sparing LLND by trained Dutch surgeons showed acceptable complication rates and good oncologic control of the lateral compartment to date.

To examine the clinical impact of transanal total mesorectal excision (TaTME) for locally advanced rectal cancer after neoadjuvant chemoradiotherapy (NACRT).

This retrospective study included 91 patients undergoing surgery for rectal cancer after NACRT between 2011 and 2022. Among them, 24, 22, and 45 patients underwent open (Open), conventional laparoscopic (Lap), and TaTME surgeries, respectively. We compared their clinical outcomes.

Operative time, blood loss, transfusion, morbidity, and hospital stay were significantly lower in the TaTME group than in the Open or Lap groups. The multivariate regression analyses identified only the TaTME approach as a significant factor for reducing morbidity. Both 3 yrear relapse-free survival (RFS) and local recurrence-free survival (LRFS) were significantly better in the TaTME group than in the Open or Lap groups (3 yr RFS: 94.7%, 80.4%, and 66.7%, and 3 yr LRFS: 100%, 90.5%, and 82.2% for the TaTME, Lap, and Open groups, respectively). Multivariate analyses of potential risk factors for recurrence identified body mass index, combined resection, and pathological stage, but not the TaTME approach, as significant predictors of recurrence.

TaTME reduced morbidity significantly in patients with locally advanced rectal cancer undergoing NACRT, compared with open or laparoscopic surgery.

The best modality for evaluating lateral pelvic lymph node (LPLN) metastases from rectal cancer remains unclear. This study compared the diagnostic ability of 1-mm computed tomography (CT) and 3-mm magnetic resonance imaging (MRI) in identifying LPLN metastases based on size.

This observational study analyzed not individual patients but 191 sides from 100 rectal cancer patients without preoperative treatment for whom preoperative CT and MRI and corresponding pathological results for LPLNs were available. A swollen LPLN was defined as an LN with a short-axis size of ≥5 mm on 1-mm CT.

LPLNs were detected significantly more frequently with 1-mm CT than with 3-mm MRI (p < 0.001). Among the 117 sides without swollen LPLNs, metastasis was observed in 1.7% of patients. In contrast, LPLN metastasis was confirmed in 28.4% of 74 sides with swollen LPLNs. In the evaluation of swollen LPLNs, 3-mm MRI yielded a 34% improvement in the diagnostic performance of LPLN metastasis over 1-mm CT (categorical net reclassification improvement: 0.341, p = 0.045).

In conclusion, 1-mm CT should be performed preoperatively to evaluate LPLNs. Further evaluations can be omitted in the absence of swollen LPLNs. In patients with swollen LPLNs, a careful assessment of LPLN metastasis should be conducted via additional MRI, even in early T-stage tumors.

Introduction: The impact of colorectal surgery on older adults' (≥65 years) health-related quality of life (HRQoL) is rarely reported. Methods: This prospective multi-institutional cohort study involving 217 participants investigated factors affecting older colorectal cancer (CRC) patients' HRQoL following surgery with the EORTC QLQ-C30 and the HADS. Results: The trend of the global QoL and individual subscales show an overall dip in QoL from baseline to pre-discharge, before slowly rising until the 6-month mark. Baseline score of individual outcome measures was the only constant predictor of the outcome measure over time. Conclusion: Age was not found to be a significant predictor of HRQoL in older adults undergoing colorectal surgery, while baseline scores of individual outcome measures consistently predicted post-operative HRQoL scores. Interventions should be targeted at specific subgroups of older adults scheduled for colorectal surgery, such as those with lower baseline scores.

Differences in oncological outcomes between conservative and surgical treatments for anastomotic leakage (AL) in patients undergoing colorectal cancer surgery remain unclear.

From July 2011 to June 2020, 385 patients underwent curative resection with double-stapling anastomosis for left-sided colon and rectal cancers. Among them, 33 patients who experienced AL were retrospectively evaluated and categorized into two groups: conservative (n = 20) and surgical (n = 13). In the surgical group, abdominal lavage using a sufficient amount of normal saline was performed during reoperation. The primary endpoint was the 3-year cumulative incidence of local recurrence (LR).

Seven (21.2%) patients in the conservative group experienced LR, while none in the surgical group. Survival analysis indicated no differences in overall and recurrent-free survival. However, the 3-year cumulative incidence of LR was significantly lower in the surgical group than in the conservative group (0% versus 31.3%, p=0.045).

Differences in AL management were associated with oncological outcomes, specifically a decreased LR. Therefore, surgeons should consider our findings when determining the most appropriate AL treatment to improve oncological outcomes.

Since the adoption of neoadjuvant chemoradiation and total mesorectal excision as the standard in rectal cancer care, there has been marked improvement in the local recurrence rates. In this context, restaging magnetic resonance imaging (MRI) plays a key role in the assessment of tumor response, occasionally enabling organ-sparing approaches. However, the role of restaging MRI in evaluating lateral lymph nodes remains limited. Most studies suggest a high risk of lateral local recurrence regardless of a decrease in lymph node size on restaging MRI. Therefore, it is recommended that clinical decisions should rely on the primary MRI scan. Watchful waiting may be appropriate only in cases of a clinical complete response with substantial downsizing of lateral lymph nodes (≤ 4.0 mm). Notably, some lateral lymph nodes may enlarge during follow-up despite complete tumor response, in which case, lateral lymph node dissection can be considered while preserving the rectum. Thus, continuous surveillance of lateral lymph nodes is essential during watchful waiting. Restaging MRI may hold greater importance for smaller lymph nodes (5.0-6.9 mm), as those with persistent malignant features on imaging carry a 13% risk of lateral recurrence at 4 years. Understanding these risks is critical when engaging in shared decision-making with the patient.

Lateral pelvic node dissection (LPLND) is indicated in the surgical management of clinically significant pelvic lymphadenopathy associated with rectal malignancies. However, procedure-related morbidity, including the incidence and predisposing factors for lymphoceles arising in this setting have not been adequately evaluated.

This retrospective single-institution study included 183 patients with nonmetastatic, lateral node-positive rectal cancer undergoing total mesorectal excision with LPLND between June 2014 and May 2023 to determine the incidence and severity of postoperative complications using the Clavien-Dindo system, with logistic regression performed to model a relationship between lymphocele-development and potentially-predictive variables.

In this cohort, mean age was 45.3 ± 12.81 years, 62.8% were male, and 27.9% had body mass index ≥ 25 kg/m2. Median tumor-distance from the verge was 3.0 (interquartile range [IQR] 1.0-5.0) cm. Following radiotherapy in 86.9%, all patients underwent surgery: 30.1% had open resection and 26.2% had bilateral LPLND. Median nodal-yield was 6 (IQR 4-8) per side. Postoperatively, 45.3% developed complications, with 18% considered clinically significant. Lymphoceles, detected in 21.3%, comprised the single-most common sequelae following LPLND, 46.2% arising within 30 days of surgery and 33.3% requiring intervention. On multivariate analyses, obesity (hazard ratio [HR] 2.496; 95% confidence interval [CI] 1.094-5.695), receipt of preoperative radiation (HR 10.026; 95% CI 1.225-82.027), open surgical approach (HR 2.779; 95% CI 1.202-6.425), and number of harvested nodes (HR 1.105; 95% CI 1.026-1.190) were significantly associated with lymphocele-development.

Pelvic lymphoceles and its attendant complications represent the most commonly encountered morbidity following LPLND for rectal cancer, with obesity, neoadjuvant radiotherapy, open surgery, and higher nodal-yield predisposing to their development.

Chemoradiotherapy (CRT) for rectal cancer is limited by its harmful side effects and its insufficient benefit on lateral lymph node metastases. The purpose of this study was to evaluate the long-term outcomes of S-1 and oxaliplatin with total mesorectal excision (TME) and lateral lymph node dissection (LLND) without radiation for rectal cancer.

The inclusion criteria were patients with stage II or III rectal cancer located within 10 cm from the anal verge. Fifty-two patients who underwent neoadjuvant chemotherapy (NAC) followed by TME and LLND were evaluated. The primary endpoint was the 3-year local recurrence. The secondary endpoints were the 3-year rates of relapse-free survival and overall survival. Expected post-NAC and surgical outcomes were prospectively analyzed.

The overall recurrence rate was 15.4%, with eight patients developing distant recurrences. The local recurrence rate was 7.7% (n = 4). Among the 4 patients with local recurrence, 3 (5.8%) patients had central pelvis recurrence, and 1 (1.9%) patient had lateral pelvic recurrence. The 3-year survival rate was 98.1%, and the 3-year relapse-free survival rate was 84.6%. The risk factors for local recurrence were mucinous carcinoma (p = 0.016) and a positive resection margin (p = 0.009). Pathological mesorectal lymph node metastasis and local recurrence were independent risk factors for poor survival.

Although preoperative chemotherapy and TME with LLND are sufficient to control local recurrence, some cases will require more aggressive chemotherapy with radiation therapy.

This study aimed to identify cases in which lateral lymph node (LLN) dissection (LLND) can be excluded by clarifying preoperative factors, including an evaluation of the middle rectal artery (MRA), associated with LLN metastasis.

Fifty-five consecutive patients who underwent preoperative positron emission tomography-computed tomography (PET/CT) and total mesorectal excision with LLND for rectal cancer were included. We retrospectively investigated the preoperative clinical factors associated with pathological LLN (pLLN) metastasis. We analyzed the regions of pLLN metastasis using MRA.

pLLN metastasis occurred in 13 (23.6%) patients. According to a multivariate analysis, clinical LLN (cLLN) metastasis based on short-axis size and LLN status based on PET/CT were independent preoperative factors of pLLN metastasis. The negative predictive value (NPV) was high (97.1%) in patients evaluated as negative based on PET/CT and cLLN short-axis size. MRA was detected in 24 patients (43.6%) using contrast-enhanced CT, and there was a significant relationship between pLLN metastasis and the presence of MRA. pLLN metastasis in the internal iliac region but not in the obturator region was significantly correlated with the presence of MRA.

Combined cLLN metastasis based on short-axis size and PET/CT showed a higher NPV, suggesting this to be a useful method for identifying cases in which LLND can be excluded.

Pelvic lymph node dissection (PLND) is important for accurate staging and prognosis of prostate and/or bladder cancer. Several guidelines recommend extended PLND for patients with these cancers. However, the therapeutic benefits of extended PLND are unclear. One major reason is that the extent of PLND is not clearly defined. Thus, the working group for standardization of robot-assisted PLND, including nine experienced urologists for PLND in Japan, was launched in January 2023 by the Japanese Society of Endourology and Robotics. This study summarized the discussions to define the individual extent of PLND in urological surgery in a consensus meeting among these experienced urologists. The consensus meeting determined the extent of PLND based on arteries (veins) and anatomical membrane structures rather than a vague concept or approach toward PLND. This concept is expected to allow surgeons to implement the same extent of PLND. Finally, after a total of 10 online web conferences were held, we determined the extent of PLND for the obturator lymph node (LN) area, the internal iliac LN area, the external and common iliac LN area, and the presacral LN area according to the above rules. The extent of PLND suggested here currently does not have a clear therapeutic rationale. Therefore, the extent of our proposed PLND is by no means mandatory. We hope our definition of the extent of PLND will be supported by further evidence of therapeutic benefits for urologic cancers.

Lateral lymph node dissection (LLND) can decrease local recurrence to lateral compartments in middle-low rectal cancer, but pathological evidence for optimal surgical indications, especially after neoadjuvant (chemo)radiotherapy (nCRT), is lacking. This study aimed to identify the predictive factors and oncological outcomes for different LLN locations associated with pathological metastasis.

In this multicenter study, patients from 19 centers who underwent total mesorectal excision (TME) with LLND for locally advanced mid-/low rectal cancer from January 2012 to December 2021 were included.

All 566 included patients underwent TME with LLND surgery; 241 (37.4%) of the largest LLNs were located in the obturator area, and 403 (62.6%) of the largest LLNs were located in the internal iliac area. Multivariate analysis revealed that a short-axis size of 9 mm for the obturator area and 6 mm for internal iliac nodes constituted a reliable indicator of pathological LLN metastasis in non-CRT patients. In nCRT patients, a short-axis node size of 7 mm for obturator nodes and 4 mm for internal iliac nodes could be used to accurately predict pathological LLN metastasis. In contrast to pathological internal iliac node metastasis, pathological obturator node metastasis was associated with lower distant metastasis-free survival (DMFS) (P = 0.001), cancer-specific survival (CSS) (P = 0.043), and overall survival (OS) (P = 0.009), but lower lateral local recurrence-free survival (LRFS) (P > 0.05) was not statistically significant.

The obturator and internal iliac nodes may be two completely different types of LLNs, and the optimal cutoff value for predicting pathological LLN metastasis is inconsistent regardless of nCRT. Clinical trial registration The protocol of the current study was registered on ClinicalTrials.gov (NCT04850027), and the protocols were in accordance with the standards set by the World Medical Association Declaration of Helsinki.

Inadequate treatment of enlarged lateral lymph nodes (LLNs) in rectal cancer patients is associated with an increased lateral local recurrence (LLR) risk, despite neoadjuvant treatment and total mesorectal excision (TME) surgery. There is a promising role for LLN dissection (LLND) to lower this risk, but this challenging procedure requires appropriate training. This study protocol describes a prospective evaluation of oncological outcomes after standardised treatment based on multidisciplinary training, thereby aiming for a 50% reduction in LLR rate.

A prospective registration study will be opened in hospitals in which the involved multidisciplinary team members (radiologists, radiation oncologists, surgeons and pathologists) have received dedicated training to enhance knowledge and awareness of LLNs and in which standardised treatment including LLND has been implemented. Patients with rectal cancer and at least one enlarged LLN (short-axis ≥7.0 mm), or intermediate LLN (short-axis 5.0-6.9 mm) with at least one malignant feature on primary MRI, evaluated by a trained radiologist, are eligible. Patients will undergo neoadjuvant treatment by trained radiation oncologists, followed by TME surgery in combination with a minimally invasive, nerve-sparing LLND performed by trained surgeons. LLND specimens are evaluated by trained pathologists or grossing assistants. The primary outcome is LLR rate 3 years postoperatively. Secondary outcomes are morbidity, disease-free survival, overall survival and quality of life. To demonstrate a significant reduction in LLR rate from 13% (based on historical control data) to 6% after optimised treatment, 200 patients with enlarged LLNs are required.

The medical ethics board of the Vrije Universiteit Medical Centre (VUMC), the Netherlands, approved the study on 23 November 2022 (reference: 2021.0524). Participating centres must obtain local approval and participants are required to provide written informed consent. Results obtained from this study will be communicated via peer-reviewed medical journals and presentations at conferences.

NCT04486131, 24 July 2020, https://clinicaltrials.gov/ct2/show/NCT04486131.

Lateral pelvic lymph node dissection is performed for selected patients with rectal cancer with persistent lateral nodal disease after neoadjuvant therapy. This technique has been slow to be adopted in the West because of concerns regarding technical difficulty. This is the first report on the learning curve for lateral pelvic lymph node dissection in the United States or Europe.

This study aimed to analyze the learning curve associated with robotic lateral pelvic lymph node dissection.

Retrospective observational cohort.

Tertiary academic cancer center.

Consecutive patients from 2012 to 2021.

All patients underwent robotic lateral pelvic lymph node dissection.

The primary end points were the learning curves for the maximum number of nodes retrieved and urinary retention, which was evaluated with simple cumulative sum and 2-sided Bernoulli cumulative sum charts.

Fifty-four procedures were included. A single-surgeon learning curve (n = 35) and an institutional learning curve are presented in the analysis. In the single-surgeon learning curve, a turning point marking the end of a learning phase was detected at the 12th procedure for the number of retrieved nodes and at the 20th procedure for urinary retention. In the institutional learning curve analysis, 2 turning points were identified at the 13th procedure, indicating progressive improvements for the number of retrieved nodes, and at the 27th procedure for urinary retention. No sustained alarm signals were detected at any time point.

The retrospective nature, small sample size, and the referral center nature of the reporting institution may limit generalizability.

In a setting of institutional experience with robotic colorectal surgery, including beyond total mesorectal excision resections, the learning curve for robotic lateral pelvic lymph node dissection is acceptably short. Our results demonstrate the feasibility of the acquisition of this technique in a controlled setting, with sufficient case volume and proctoring to optimize the learning curve. See Video Abstract.

ANTECEDENTES:La disección lateral de los ganglios linfáticos pélvicos se realiza en pacientes seleccionados con cáncer de recto con enfermedad ganglionar lateral persistente tras el tratamiento neoadyuvante. La adopción de esta técnica en Occidente ha sido lenta debido a la preocupación por su dificultad técnica. Éste es el primer informe sobre la curva de aprendizaje de la disección de los ganglios linfáticos pélvicos laterales en EE.UU. o Europa.OBJETIVO:El objetivo de este estudio fue analizar la curva de aprendizaje asociada a la disección robótica de los ganglios linfáticos pélvicos laterales.DISEÑO:Cohorte observacional retrospectiva.LUGAR:Centro oncológico académico terciario.PACIENTES:Pacientes consecutivos desde 2012 al 2021.INTERVENCIÓN:Todos los pacientes fueron sometieron a disección robótica de ganglios linfáticos pélvicos laterales.PRINCIPALES MEDIDAS DE RESULTADO:Los criterios de valoración primarios fueron las curvas de aprendizaje tomando en cuenta el mayor número de ganglios recuperados y la retención urinaria que fueron evaluados con gráficos de suma acumulativa simple y de suma acumulativa de Bernoulli de dos caras.RESULTADOS:Fueron incluidos 54 procedimientos. En el análisis se presentan una curva de aprendizaje de un solo cirujano (n = 35) y una curva de aprendizaje institucional. En la curva de aprendizaje de un solo cirujano, se detectó un punto de inflexión que marcaba el final de una fase de aprendizaje en el duodécimo procedimiento para el número de ganglios extraídos y en el vigésimo para la retención urinaria. En el análisis de la curva de aprendizaje institucional, se identificaron dos puntos de inflexión en las intervenciones 13.ª y 26.ª, que indicaron mejoras progresivas en el número de ganglios extraídos, y en la 27.ª en la retención urinaria. No se detectaron señales de alarma sostenidas en ningún momento.LIMITACIONES:La naturaleza retrospectiva, el pequeño tamaño de la muestra y la naturaleza de centro de referencia de la institución informante que pueden limitar la capacidad de generalizarse.CONCLUSIONES:En un entorno de experiencia institucional con cirugía robótica colorrectal incluyendo más allá de las resecciones TME, la curva de aprendizaje para la disección robótica de ganglios linfáticos pélvicos laterales es aceptablemente corta. Nuestros resultados demuestran la viabilidad de la adquisición de esta técnica en un entorno controlado, con un volumen de casos suficiente y una supervisión que puede optimizar la curva de aprendizaje. (Traducción-Dr. Osvaldo Gauto ).

The population in Western countries differs significantly from that in Eastern countries, and the prevalence of lateral pelvic lymph node (LPLN) involvement in Western populations remains largely unknown due to the limited application of LPLN dissection (LPLND). This discrepancy is primarily attributed to the higher body mass index commonly observed in Western populations, which increases the risk of intraoperative complications. Consequently, the aim of this study is to describe a specific Western clinico-radiological selection tool for LPLND, namely, the lateral pelvic lymph node positivity (LPLNP) score.

This retrospective single center study was designed to elaborate the LPLNP score, which was further tested on a prospective cohort of patients. Clinical and MRI factors associated with LPLN involvement were identified, and logistic regression was used to establish the LPLNP score.

In the retrospective series, 120 patients underwent lateral pelvic lymph node dissection. After stepwise logistic regression, five parameters were ultimately included in the LPLNP score. When tested on 66 prospectively selected patients, 40 with an LPLNP score > 0.23 (corresponding to the highest sensitivity and specificity) underwent LPLND: 22 patients (55%) had pathologically confirmed positive LPLN. The negative predictive value of the LPLNP score was 96%, with a sensitivity of 95.7% and a specificity of 58.1%.

The LPLNP score was developed based on the largest group of Western patients with locally advanced rectal cancer. This scoring system demonstrated high sensitivity and specificity during validation on the prospective series, correctly identifying LPLN involvement in 55% of cases.

The purpose of this study is to examine the appropriateness of MRI navigation surgery following chemoradiotherapy (CRT), including lateral pelvic lymph node dissection (LLND) for middle to low rectal cancer.

Forty-three consecutive patients with cT2-4b rectal cancer within 10 cm from the anal verge who underwent laparoscopic radical surgery following CRT (45-50.4Gy + S1 80mg/m2) from January 2014 and February 2020 were analyzed. We decided on the operative procedure, including LLND, based on the restaging MRI. We examined the rates of 3-year postoperative local pelvic recurrence, permanent stoma, and recurrent risk factors (Group S). We also compared the results to that of the fourteen patients who enrolled in the previous phase II trial and underwent laparoscopic radical surgery following CRT (40Gy + S-1 (80mg/m2) or UFT (300 mg/m2)) for consecutive cT2-4b rectal cancer below the peritoneal reflection. The operative procedure was decided at the initial MRI diagnosis, and the LLND was not performed (Group P).

We had no local pelvic recurrence in Group S, and the three-year local pelvic recurrence-free survival was significantly better in Group S than P (100 % in S 85.1 % in P, p < 0.05). The permanent stoma rate was not different between the Groups, irrespective of the significantly high rate of cCRM(+) in Group S. The Cox proportional hazards model for significant factors of recurrence on the univariate analysis revealed that ycM and ycEMVI scores were independently significant (p < 0.001).

MRI navigation surgery, including LLND for rectal cancer following chemoradiotherapy, improves local control and functional preservation.

Lateral lymph node dissection and its inclusion in the treatment of rectal cancer is a controversial issue, with great differences, especially between Eastern and Western countries. Studies try to highlight the superiority of resection of these lymph nodes compared to simple mesorectal resection in terms of local recurrence of the disease, the overall survival of patients, and additional postoperative complications. In this study, the modern literature was reviewed, with the ultimate goal of clarifying the exact importance of lateral lymph node dissection, in terms of oncological outcome in patients with cancer of the middle and lower rectum, by studying the involvement of this lymph node dispersion in terms of local recurrence and overall survival of patients with rectal cancer. This review was carried out using electronic databases, including PubMed, Embase, and MEDLINE, with studies dating back to the last decade. Of the 31 studies that were eventually included in the final review, there is no statistically clear superiority and real benefit from lymph node resection beyond the lymph nodes of the mid-rectum. European guidelines are set against lateral lymph node dissection, except for lymph nodes that show suspicious features on preoperative imaging. In contrast, in Eastern countries, total mesorectal excision (TME) with extensive simultaneous resection of the lateral pelvic lymph nodes (LPLNs) is the protocol followed. Recent studies focus on the subcategory of patients with non-responsive to adjuvant therapy, lateral lymph nodes, in which the ultimate benefit of extensive lymph node dissection is explored. The decision to join the TME procedure for the removal of the LPLNs is a subject of intense research. There are no data on the criteria for determining these lymph nodes as an increased risk of metastatic outbreaks. Despite the great clinical and research interest worldwide nowadays, the resection of LPLNs remains a controversial issue of debate, with intense disagreements according to geographical area, while the existence of additional studies is necessary to come to final conclusions.

This study attempted to compare short-term outcomes of laparoscopic surgery (LS), robot-assisted laparoscopic surgery (RS), and open surgery (OS) for lateral lymph-node dissection (LLND) in treatment of rectal cancer through network meta-analysis. Embase, Web of Science, PubMed, and The Cochrane Library databases were searched to collect cohort studies on outcomes of LS, RS, and OS for LLND for rectal cancer. Newcastle-Ottawa Scale (NOS) was utilized to evaluate the quality of cohort studies. Primary outcomes should at least include one of the following clinical outcome measures: operative time, blood loss, total lymph-node harvest, positive resection margin rate, postoperative complications, and postoperative hospital stay. A network meta-analysis was conducted using STATA software. Fourteen cohort studies including 8612 patients were eligible for inclusion. The network meta-analysis results showed that, in terms of intraoperative outcomes, the RS group had the longest operative time, while the OS group had the shortest; the LS and RS groups had significantly less blood loss than the OS group. In terms of histological outcomes, there were no significant differences in the total number of lymph nodes harvested and the positive margin rate among the LS, RS, and OS groups (P > 0.05). Regarding postoperative outcomes, the OS group had the highest probability of postoperative complications and the longest hospital stay, followed by the LS group, with the RS group being the lowest. RS was the best method in blood loss, postoperative complication rate, and postoperative hospital stay, followed by LS. OS had the shortest operative time and the highest blood loss.

The role of lateral pelvic lymph node dissection in the treatment of patients with locally advanced rectal cancer is a matter of controversy. Surgical practices in Korea and Japan have accepted this approach and are widely utilized; however, it is not routinely incorporated in the practice of countries in the Western hemisphere. This review will examine the role of lateral pelvic lymph node dissection.

To develop a magnetic resonance imaging (MRI)-based radiomics model for preoperative prediction of lateral pelvic lymph node (LPLN) metastasis (LPLNM) in patients with locally advanced rectal cancer MATERIALS AND METHODS: We retrospectively enrolled 263 patients with rectal cancer who underwent total mesorectal excision and LPLN dissection. Radiomics features from the primary lesion and LPLNs on baseline MRI images were utilized to construct a radiomics model, and their radiomics scores were combined to develop a radiomics scoring system. A clinical prediction model was developed using logistic regression. A hybrid predicting model was created through multivariable logistic regression analysis, integrating the radiomics score with significant clinical risk factors (baseline Carcinoembryonic Antigen (CEA), clinical circumferential resection margin status, and the short axis diameter of LPLN). This hybrid model was presented with a hybrid clinical-radiomics nomogram, and its calibration, discrimination, and clinical usefulness were assessed.

A total of 148 patients were included in the analysis and randomly divided into a training cohort (n = 104) and an independent internal testing cohort (n = 44). The hybrid clinical-radiomics model exhibited the highest discrimination, with an area under the receiver operating characteristic (AUC) of 0.843 [95% confidence interval (CI), 0.706-0.968] in the testing cohort compared to the clinical model [AUC (95% CI) = 0.772 (0.589-0.856)] and radiomics model [AUC (95% CI) = 0.731 (0.613-0.849)]. The hybrid prediction model also demonstrated good calibration, and decision curve analysis confirmed its clinical usefulness.

This study developed a hybrid MRI-based radiomics model that incorporates a combination of radiomics score and significant clinical risk factors. The proposed model holds promise for individualized preoperative prediction of LPLNM in patients with locally advanced rectal cancer.

The data presented in this study are available on request from the corresponding author.

Standard of care for most patients with locally advanced rectal cancer in The Netherlands consists of neoadjuvant chemoradiotherapy (nCRT) followed by resection. Enlarged lateral lymph nodes (LLNs), especially in the iliac compartment, appears to be associated with an increased risk of local recurrence. Little is known about the risk of local recurrence after nCRT.

This study included patients with locally advanced rectal cancer and enlarged LLNs on pretreatment MRI-scan located in the internal iliac, obturator, external iliac, or common iliac compartment. Patients were treated with nCRT and response to therapy was evaluated with MRI-scan. The primary endpoint was local lateral recurrence after nCRT. Secondary endpoints included overall survival and postoperative complications.

Out of 260 patients treated for rectal cancer, a total of 46 patients with enlarged LLNs (18% of all patients) were included between 2012 and 2019 in 2 Dutch hospitals. No patients had lateral lymph node recurrence (LLNR) after nCRT. Only 1 patient had local recurrence of rectal cancer after radical resection during a median follow up of 3 years. Disseminated disease was seen in 12 patients and 9 patients died during follow-up, which result in an overall survival rate of 80.4%. Postoperative complications were seen in 41% of patients. There was no 90-days postoperative mortality.

Enlarged LLNs are rare after nCRT and no LLNR was found after nCRT in our study population. This could suggest that nCRT only with or without an extra radiotherapeutic boost on enlarged LLNs already reduces the risk of LLNR.

Total neoadjuvant therapy (TNT) is a novel strategy for rectal cancer that administers both (chemo)radiotherapy and systemic chemotherapy before surgery. TNT is expected to improve treatment compliance, tumor regression, organ preservation, and oncologic outcomes. Multiple TNT regimens are currently available with various combinations of the treatments including induction or consolidation chemotherapy, triplet or doublet chemotherapy, and long-course chemoradiotherapy or short-course radiotherapy. Evidence on TNT is rapidly evolving with new data on clinical trials, and no definitive consensus has been established on which regimens to use for improving outcomes. Clinicians need to understand the advantages and limitations of the available regimens for multidisciplinary decision making. This article reviews currently available evidence on TNT for rectal cancer. A decision making flow chart is provided for tailor-made use of TNT regimens based on tumor location and local and systemic risk.

Lateral lymph node dissection (LLND) for rectal cancer is still not a widely established technique owing to the existing controversy between Eastern and Western countries and the lack of well-designed studies. The risk of complications and the paucity of long-term oncological results are significant drawbacks for further applying this technique. The use of indocyanine green (ICG) near-infrared (NIR) fluorescence for LLND appears as a promising technique for enhancing postoperative and oncological outcomes. This review aims to evaluate the emerging role of ICG during LLND and present the benefits of its application.

Systematic electronic research was conducted in PubMed and Google Scholar using a combination of medical subject headings (MeSH). Studies presenting the use of ICG during LLND, especially in terms of harvested lymph nodes, were included and reviewed. Studies comparing LLND with ICG (LLND + ICG) or without ICG (LLND-alone) were further analyzed for the number of lymph nodes and postoperative outcomes.

In total, 13 studies were found eligible and analyzed for different parameters. LLND + ICG is associated with significantly increased number of harvested lateral lymph nodes (p < 0.05), minor blood loss, decreased operative time, and probably decreased urinary retention postoperatively compared with LLND-alone.

The use of ICG fluorescence during LLND is a safe and feasible technique for balancing postoperative outcomes and the number of harvested lymph nodes. Well-designed studies with long-term results are required to elucidate the oncological benefits and establish this promising technique.

The potential benefits of robotic-assisted compared with laparoscopic surgery for locally advanced cancer have not been sufficiently proven by prospective studies. One factor is speculated to be the lack of strict surgeon criteria. The aim of this study was to assess outcomes for robotic surgery in patients with locally advanced rectal cancer with strict surgeon experience criteria.

A criterion was set requiring surgeons to have performed more than 40 robotically assisted operations for rectal cancer. Between March 2020 and May 2022, patients with rectal cancer (distance from the anal verge of 12 cm or less, cT2-T4a, cN0-N3, cM0, or cT1-T4a, cN1-N3, cM0) were registered. The primary endpoint was the rate positive circumferential resection margin (CRM) from the pathological specimen. Secondary endpoints were surgical outcomes, pathological results, postoperative complications, and longterm outcomes.

Of the 321 registered patients, 303 were analysed, excluding 18 that were ineligible. At diagnosis: stage I (n = 68), stage II (n = 84) and stage III (n = 151). Neoadjuvant therapy was used in 56 patients. There were no conversions to open surgery. The median console time to rectal resection was 170 min, and the median blood loss was 5 ml. Fourteen patients had a positive CRM (4.6%). Grade III-IV postoperative complications were observed in 13 patients (4.3%).

Robotic-assisted surgery is feasible for locally advanced rectal cancer when strict surgeon criteria are used.

Although several recent meta-analyses have investigated the clinical influence of the addition of lateral lymph node dissection (LLND) on oncologic outcomes in patients with mid-low rectal cancer (RC) undergoing mesorectal excision (ME), most studies included in such meta-analyses were retrospectively designed. Therefore, this study aimed to explore the clinical influence of prophylactic LLND on oncologic outcomes in patients with mid-low RC undergoing ME.

A comprehensive electronic search of the literature up to July 2022 was performed to identify studies that compared oncologic outcomes between patients with mid-low RC undergoing ME who underwent LLND and patients with mid-low RC undergoing ME who did not undergo LLND. A meta-analysis was performed using fixed-effects models and the generic inverse variance method to calculate hazard ratios (HRs) and 95% CIs, and heterogeneity was analyzed using I2 statistics.

A total of 6 studies, consisting of 3 randomized and 3 propensity score matching studies, were included in this meta-analysis. The results of the meta-analysis of 2 randomized studies demonstrated no significant effect of prophylactic LLND on improving oncologic outcomes concerning overall survival (OS) (HR, 1.22; 95% CI, 0.89-1.69; I2 = 0%; P = .22) and relapse-free survival (RFS) (HR, 1.03; 95% CI, 0.81-1.31; I2 = 28%; P = .83).

The results of this meta-analysis revealed no significant influence of prophylactic LLND on oncologic outcomes-OS and RFS-in patients with mid-low RC who underwent ME.

Robotic lateral lymph node dissection (LLND) has been described as a safe and feasible procedure for local advanced rectal cancer. The aim of this study was to evaluate the learning curve for robotic-assisted LLND.

We collected data on 78 consecutive patients who underwent robotic-LLND at our hospital. The learning curve was analyzed using the cumulative sum (CUSUM) method to assess changes in the unilateral LLND operative times across the case sequence.

Among the 78 patients, 52 underwent bilateral LLND and 26 underwent unilateral LLND. A total of 130 consecutive data were recorded. We arranged unilateral robotic-LLND operative times and calculated cumulative sum values, allowing the differentiation of three phases: phase I (learning period, cases 1-51); phase II (proficiency period, cases 52-83); and phase III (mastery period, cases 84-130). As the learning curve accumulated, the operation time and estimated blood loss of unilateral robotic-LLND decreased significantly with each phase (P < 0.05). By 12 months after surgery, the International Prostatic Symptom Score of patients at phase III was significantly lower than at phase I (P < 0.05).

The CUSUM curve shows three phases in the learning of robotic-LLND. The estimated learning curve for robotic-assisted rectal-LLND is achieved after 51 cases.

Whether lateral pelvic node metastasis should be considered as a regional or systemic disease is a long-standing debate. Although previous Japanese studies have considered it to be locoregional disease, Western countries consider it a systemic disease and do not perform lateral pelvic node dissection after preoperative chemoradiotherapy.

To evaluate whether lateral pelvic node metastasis is a systemic or regional disease that is amenable to curative resection.

Retrospective analysis of a prospectively collected database.

This study was conducted at a tertiary cancer center.

There were 616 consecutive patients who underwent curative total mesorectal excision alone or with lateral pelvic node dissection after preoperative chemoradiotherapy for locally advanced rectal cancer between 2011 and 2019.

Three-year disease-free and overall survival.

A total of 360 patients underwent total mesorectal excision, and 160 patients underwent total mesorectal excision with lateral pelvic node dissection. There was no difference in the 3-year disease-free survival (DFS; p = 0.844) or overall survival rates ( p = 0.921) between the groups. Patients with lateral pelvic node metastasis showed DFS similar to those with perirectal lymph node metastasis in the total mesorectal excision group. In a subgroup analysis, patients with internal iliac pelvic node metastasis showed a disease-free survival comparable to those with perirectal node involvement, and patients with other lateral pelvic node metastasis showed a DFS similar to those with intermediate node involvement. In the lateral pelvic node dissection group, the lateral pelvic node metastatic rate was 32.5%. On multivariate analysis, fewer than 8 of the unilateral harvested lateral pelvic nodes and advanced ypT stage were significantly associated with poor disease-free survival.

The retrospective design.

Lateral lymphatic metastasis showed oncologic outcomes similar to those of upward spread, especially perirectal lymph nodes metastasis. Large cohort studies with long-term follow-up are required to confirm these results. See Video Abstract .

ANTECEDENTES:Es un debate muy antiguo si las metástasis en los ganglios pélvicos laterales deben considerarse una enfermedad regional o sistémica. Si bien estudios japoneses anteriores las consideran como una enfermedad locorregional, en los países de occidente se las considera como una enfermedad sistémica por la cual no se realiza disección de ganglios pélvicos laterales después de una radioquimioterapia preoperatoria.OBJETIVOS:Evaluar si la metástasis en los ganglios pélvicos laterales se consideran como enfermedad sistémica o enfermedad regional susceptible de resección curativa.DISEÑO:Análisis retrospectivo de una base de datos recopilada prospectivamente.AJUSTE:Este estudio se realizó en un centro oncológico terciario.PACIENTES:616 pacientes consecutivos se sometieron a excisión total del mesorrecto curativa sola o con disección de los ganglios pélvicos laterales después de radioquimioterapia preoperatoria en casos de cáncer de recto localmente avanzado entre 2011 y 2019.PRINCIPALES MEDIDAS DE RESULTADO:Sobrevida global y libre de enfermedad a 3 años.RESULTADOS:Un total de 360 pacientes se sometieron a excisión total del mesorrecto y 160 pacientes se sometieron a excisión total del mesorrecto con disección de ganglios pélvicos laterales.No hubo diferencias en la sobrevida libre de enfermedad a 3 años (p = 0,844) ni en las tasas de sobrevida general (p = 0,921) entre los grupos. Los pacientes con metástasis en los ganglios pélvicos laterales mostraron una sobrevida libre de enfermedad similar a aquellos con metástasis en los ganglios linfáticos perirrectales que se encontraban en el grupo de excisión total del mesorrecto.En el análisis de subgrupos, los pacientes con metástasis en los ganglios pélvicos ilíacos internos mostraron una sobrevida libre de enfermedad comparable a aquellos con afección de los ganglios perirrectales y los pacientes con otras metástasis en los ganglios pélvicos laterales mostraron una sobrevida libre de enfermedad similar a aquellos con afección de los ganglios intermedios.En el grupo de disección de los ganglios pélvicos laterales, la tasa de metástasis en dichos ganglios fué del 32,5%. En el análisis multivariado, < de 8 ganglios pélvicos laterales resecados unilateralmente y el estadio ypT avanzado se asociaron significativamente con una menor sobrevida libre de enfermedad.LIMITACIÓN:El diseño retrospectivo del estudio.CONCLUSIONES:Las metástasis linfáticas laterales mostraron resultados oncológicos similares a la diseminación ascendente, especialmente las metástasis en los ganglios linfáticos perirrectales. Se requieren grandes estudios de cohortes con seguimiento a largo plazo para confirmar estos resultados. (Traducción-Dr. Xavier Delgadillo ).

(1) Introduction: The laparoscopic approach to low pelvic tumors is challenging and hindered by suboptimal tumor visualization and dissection, with possible oncological failure. Stereotactic navigation provides real-time image guidance that may optimize safety, accuracy, and precision when dissecting challenging low pelvic tumors. (2) Methods: Preoperative CT images were acquired with eight skin-fixed fiducials and loaded into a navigation system. A patient tracker was mounted on the bed side. Patient-to-image paired point registration was performed, and an instrument tracker was mounted on a laparoscopic instrument and calibrated for instrument tracking. Surgical operations were performed with real-time stereotactic navigation assistance. (3) Results: Three patients underwent stereotactic navigation surgery. Fiducial registration errors were good to optimal (±1.9, ±3.4, and ±3.4 mm). Lesions were easily identified and targeted with real-time navigation. Surgeries were uneventful. Histopathology examinations identified one retro-rectal schwannoma, one lateral pelvic recurrence from rectal adenocarcinoma, and one advanced anal canal carcinoma. No navigation-related complications, readmissions, or postoperative mortalities were observed. (4) Conclusions: The application of laparoscopic stereotactic navigation surgery to complex low pelvic tumors is feasible and could impact oncological surgical quality by enabling tumor targeting and ensuring resection margins. Further wider series are needed to confirm stereotactic navigation's impact on challenging low pelvic tumors.

Significant controversies exist with regards to the optimal management of lateral pelvic lymph nodes metastases (mLLN) in patients with low rectal cancer. The differing views held by Japanese and Western clinicians on the management of mLLN have been well documented. However, the adequacy of pelvic lymph node dissection (PLND) or neoadjuvant chemoradiation (NACRT) alone in addition to total mesorectal excision (TME) have recently come into question, due to the relatively high incidence of lateral local recurrences following PLND and TME, or NACRT and TME alone. Recently, a more selective approach to PLND has been suggested, involving a combination of neoadjuvant therapy, followed by PLND only to patients in whom the oncological benefit is likely to outweigh the risk of potential adverse events. A number of studies have attempted to retrospectively identify certain nodal characteristics on preoperative imaging, such as nodal size, appearance, and size reduction following neoadjuvant therapy. However, no consensus has been reached regarding the optimal criteria for a selective approach to PLND, partly due to the heterogeneity and retrospective nature of most of these studies. This review aims to provide an overview of recent evidence with regards to the diagnostic challenges, considerations for, and outcomes of the current management strategies for mLLN in rectal cancer patients.

The Endoscopic Surgical Skill Qualification System (ESSQS) in Japan evaluates the surgical skills required for laparoscopic surgery as an operator as well as a supervisor. This study aimed to demonstrate the benefits of an ESSQS-certified surgeon's participation in laparoscopic rectal resections as a supervisor (assistant or advisor).

We retrospectively reviewed laparoscopic resection results for cStage II and III rectal cancer performed at 56 Japanese hospitals between 2014 and 2016. We used propensity score matching to generate paired cohorts with or without an ESSQS-certified supervisor at a one-to-one ratio. The impact of ESSQS-certified supervisors' participation on short-term outcomes was assessed. In the matched cohort, multivariable logistic regression analysis and multivariable regression analysis of postoperative complication rate and intraoperative blood loss were performed to further mitigate the impact of pathological factors.

Two groups (n = 399 each) with or without an ESSQS-certified supervisor were well matched by clinical factors. The group with an ESSQS-certified supervisor had lower blood loss (68 mL vs. 98 mL, P = 0.036) and a lower incidence of severe morbidities of Clavien-Dindo grade ≥IIIa (8.0% vs. 13.3%, P = 0.016). Multivariable logistic regression analysis and multivariable regression analysis confirmed that the attendance of ESSQS-certified supervisors reduced postoperative complication occurrence (adjusted odds ratio: 2.28, 95% confidence interval: 1.38 - 3.80, P = 0.001) and intraoperative blood loss (estimated difference: -15.7 mL, P = 0.016).

This study demonstrated the educational benefits of ESSQS-certified supervisors, including assistants and advisors, evidenced by their superior short-term outcomes.

Radical surgery is the standard treatment for rectal cancer, but can impact quality of life. Recently, the concept of total neoadjuvant therapy with a watch-and-wait strategy has been proposed in which patients with a cCR after total neoadjuvant therapy do not proceed to surgery. However, most investigations of a watch-and-wait strategy have reported cases where cCR was achieved coincidentally via total neoadjuvant therapy. The aim is to assess whether total neoadjuvant therapy is effective in early-stage rectal cancer in patients that achieve cCR and are offered a watch-and-wait strategy.

JCOG2010 (TOWARd) is a multi-institutional, single-arm phase II/III confirmatory investigation of the safety and efficacy of total neoadjuvant therapy followed by a watch-and-wait strategy for rectal cancer. Key eligibility criteria include cT2-3 N0 M0 rectal adenocarcinoma, tumour diameter less than or equal to 5 cm, age 18-75 years, performance status 0-1, and no history of pelvic irradiation or rectal surgery. Total neoadjuvant therapy involves neoadjuvant chemoradiotherapy (capecitabine and radiotherapy: 45 Gy/25 fractions to the whole pelvis plus boost of 5.4 Gy/3 fractions to the primary tumour) followed by consolidation chemotherapy (four cycles of capecitabine/oxaliplatin). Patients will be re-staged every 8 weeks after total neoadjuvant therapy, and those who achieve cCR will undergo a watch-and-wait strategy, those with near complete response will undergo a watch-and-wait strategy or local resection, and those with an incomplete response will undergo radical surgery. The primary endpoint is the cCR rate in phase II and 5-year overall survival in phase III. Secondary endpoints include postoperative anal, urinary, and sexual function. A total of 105 patients (phase II, 40 patients; phase III, 65 patients) will be enrolled over 3.5 years.

This trial will determine whether total neoadjuvant therapy and a watch-and-wait strategy is an effective alternative to radical surgery for early-stage rectal cancer in patients with cT2-3 N0 M0 and tumour size less than or equal to 5 cm.

jRCTs031220288 (https://jrct.niph.go.jp/en-latest-detail/jRCTs031220288).

A watch-and-wait (WW) strategy or surgery for low to intermediate rectal cancer that has reached clinical complete remission (cCR) after neoadjuvant chemotherapy (nCRT) or total neoadjuvant therapy (TNT) has been widely used in the clinic, but both treatment strategies are controversial.

The aim of this study was to compare the oncologic outcomes of a watch-and-wait strategy or a surgical approach to treat rectal cancer in complete remission and to report the evidence-based clinical advantages of the two treatment strategies.

Seven national and international databases were searched for clinical trials comparing the watch-and-wait strategy with surgical treatment for oncological outcomes in patients with rectal cancer in clinical complete remission.

In terms of oncological outcomes, there was no significant difference between the watch-and-wait strategy and surgical treatment in terms of overall survival (OS) (HR = 0.92, 95% CI (0.52, 1.64), P = 0.777), and subgroup analysis showed no significant difference in 5-year disease-free survival (5-year DFS) between WW and both local excision (LE) and radical surgery (RS) (HR = 1.76, 95% CI (0.97, 3.19), P = 0.279; HR = 1.98, 95% CI (0.95, 4.13), P = 0.164), in distant metastasis rate (RR = 1.12, 95% CI (0.73, 1.72), P = 0.593), mortality rate (RR = 1.62, 95% CI (0.93, 2.84), P = 0.09), and organ preservation rate (RR = 1.05, 95% CI (0.94, 1.17), P = 0.394) which were not statistically significant and on the outcome indicators of local recurrence rate (RR = 2.09, 95% CI (1.44, 3.03), P < 0.001) and stoma rate (RR = 0.35, 95% CI (0.20, 0.61), P < 0.001). There were significant differences between the WW group and the surgical treatment group.

There were no differences in OS, 5-year DFS, distant metastasis, and mortality between the WW strategy group and the surgical treatment group. The WW strategy did not increase the risk of local recurrence compared with local resection but may be at greater risk of local recurrence compared with radical surgery, and the WW group was significantly better than the surgical group in terms of stoma rate; the WW strategy was evidently superior in preserving organ integrity compared to radical excision. Consequently, for patients who exhibit a profound inclination towards organ preservation and the evasion of stoma formation in the scenario of clinically complete remission of rectal cancer, the WW strategy can be contemplated as a pragmatic alternative to surgical interventions. It is, however, paramount to emphasize that the deployment of such a strategy should be meticulously undertaken within the ambit of a multidisciplinary team's management and within specialized centers dedicated to rectal cancer management.

Although previous studies have demonstrated that tumor deposits (TDs) are associated with worse prognosis in colon cancer, their clinical significance in rectal cancer has not been fully elucidated, especially in the lateral pelvic lymph node (LPLN) area. This study aimed to clarify the clinical significance of TDs, focusing on the number of metastatic foci, including lymph node metastases (LNMs) and TDs, in the LPLN area.

This retrospective study involved 226 consecutive patients with cStage II/III low rectal cancer who underwent LPLN dissection. Metastatic foci, including LNM and TD, in the LPLN area were defined as lateral pelvic metastases (LP-M) and were evaluated according to LP-M status: presence (absence vs. presence), histopathological classification (LNM vs. TD), and number (one to three vs. four or more). We evaluated the relapse-free survival of each model and compared them using the Akaike information criterion (AIC) and Harrell's concordance index (c-index).

Forty-nine of 226 patients (22%) had LP-M, and 15 patients (7%) had TDs. The median number of LP-M per patient was one (range, 1-9). The best risk stratification power was observed for number (AIC, 758; c-index, 0.668) compared with presence (AIC, 759; c-index, 0.665) and histopathological classification (AIC, 761; c-index, 0.664). The number of LP-M was an independent prognostic factor for both relapse-free and overall survival, and was significantly associated with cumulative local recurrence.

The number of metastatic foci, including LNMs and TDs, in the LPLN area is useful for risk stratification of patients with low rectal cancer.