Objective:To analyze the types and characteristics of post-operative complications in colorectal cancer patients aged over 85 years undergoing laparoscopic surgery, and to summarize peri-operative management strategies.Methods:This was an observational study. Inclusion criteria: pathologically confirmed adenocarcinoma; tumor located in ileocecum, ascending colon, transverse colon, descending colon, sigmoid colon, or rectum; undergoing laparoscopic radical resection for colorectal cancer; complete clinical data. Exclusion criteria included distant metastasis, synchronous resection of multiple primary cancers, simultaneous liver metastasis surgery, and follow-up duration <1 month. A retrospective analysis was conducted on 191 patients of colorectal cancer patients aged over 85 years who underwent laparoscopic radical surgery in the General Surgery Department at Peking Union Medical College Hospital from January 2019 to January 2024. Among 191 patients, 107 patients (56.0%) had colon cancer and 84 (44.0%) rectal cancer. All patients received "home-based prehabilitation" and post-operative "enhanced recovery after surgery" protocols. Patient characteristics, peri-operative complication types, treatments, and outcomes were analyzed.Results:Post-operative complications occurred in 97 patients (50.8%), including 53 colon cancer patients (54.6%) and 44 rectal cancer patients (45.4%). Comorbidities existed in 88 patients (90.7%), with 93 patients (95.9%) classified as ASA II-III pre-operatively and 86 (88.7%) having nutritional risks. Surgical procedures included Dixon procedure (38 patients, 39.2%), right hemicolectomy (33 patients, 34.0%), sigmoidectomy (10 patients, 10.3%), and 17 patients (17.5%) received prophylactic stomas. Complication types comprised non-anastomotic infections (38 patients, 19.9%), intestinal flora disorder (26 patients, 13.6%), anastomotic/wound/stoma-related complications (16 patients, 8.4%), thrombotic/hemorrhagic events (6 patients, 3.1%), and others (11 patients, 5.8%). By Clavien-Dindo classification: Grade I (12 patients, 6.3%), Grade II (69 patients, 36.1%), Grade III (12 patients, 6.3%), and Grade IV (4 patients, 2.1%). Except for 5 patients (2.6%) requiring unplanned re-operation, all complications resolved with conservative treatment. The median duration of post-operative hospitalization was 9.5 days (7–13).Conclusion:Non-anastomotic infections and intestinal flora disorder constitute predominant complications after laparoscopic surgery in colorectal cancer patients aged over 85 years, mostly manageable with conservative treatment. Strengthened peri-operative management incorporating pre-operative prehabilitation and post-operative enhanced recovery after surgery protocols is crucial for patients aged over 85 years.

Objective:To evaluate the clinical features and risk factors of anastomotic leakage (AL) in patients with locally advanced rectal cancer (LARC) receiving neoadjuvant chemoradiotherapy (nCRT) followed by laparoscopic radical resection and proctocol ostomy.Method:Clinicla data of LARC patients receiving neoadjuvant chemoradiotherapy followed by laparoscopic radical resection and proctocol ostomy admitted to Peking Union Medical College Hospital between Jan 2019 and Oct 2023 was enrolled. According to the occurrence of AL, patients were divided into AL group and non-AL group.Results:After propersity matching score(PSM), there were 40 patients (33.4%) and 80 patients (66.6%) in the AL and non-AL group, respectively. The first-onset symptoms of AL were abnormal character and color of the drainage (23 cases, 57.5%) and fever (14 cases, 35.0%). About 82.5% of the AL were graded as B,and all 36 patients (90.0%) were managed consveratively by fully drainage anti-infection therapy. Logistic regression analysis indicated that tumor circumferential range more than 1/2 cycle ( OR=5.95, 95% CI:2.12-1.67, P=0.004), male ( OR=4.28, 95% CI:1.22-15.00, P=0.023) and high-ligation of Inferior mesenteric artery ( OR=8.08, 95% CI:1.86-37.78, P=0.006) were independent risk factors of AL. Conclusions:In this series, grade-B AL ranks the top of the incidence, and all were cured by conservative therapy. Special attention should be paid to those patients with the characteristics of male, tumor circumferential range more than 1/2 cycle, and high-ligation of inferior mesenteric artery.

Background and Aims:For patients with mid-to-low rectal cancer who achieve clinical complete response(cCR)or near-cCR after neoadjuvant chemoradiotherapy(nCRT),the key concern for both clinicians and patients is how to preserve anal function as much as possible without significantly compromising oncological outcomes.This study was performed to evaluate the safety and feasibility of local excision as an anus-preserving approach in rectal cancer patients with cCR or near-cCR.Methods:A retrospective analysis was conducted on 51 patients with mid-to-low rectal cancer who underwent local resection after achieving cCR or near-cCR following nCRT at Peking Union Medical College Hospital,Chinese Academy of Medical Sciences,between March 2014 and July 2023.The clinical characteristics,imaging and pathological findings,surgical outcomes,as well as oncological and functional results were reviewed.Results:Among the 51 patients,34 were male and 17 were female,with a mean age of 61±14 years.Pre-nCRT imaging staging showed:cT1-2N0 in 12 cases(23.5％),cT3N0 in 13 cases(25.5％),cT1-3N0-1 in 19 cases(37.4％),and cT1-3N2 in 7 cases(13.7％).The average tumor distance from the anal verge was(4.5±1.1)cm.After achieving cCR or near-cCR following nCRT,all patients underwent local resection:40 cases(78.4％)underwent transanal endoscopic microsurgery(TEM),7 cases(13.7％)underwent transanal minimally invasive surgery(TAMIS),and 4 cases(7.8％)underwent conventional transanal local excision.The postoperative complication rate was 27.5％(14/51),with 71.4％classified as Clavien-Dindo grade Ⅰ.Postoperative histopathology showed ypT0 in 26 cases(51.0％),ypT1 in 8 cases(15.7％),ypT2 in 16 cases(31.4％),and ypT3 in 1 case(2.0％).The concordance rate between pathological results and preoperative imaging was 54.9％.Over a median follow-up of 60 months(range:34-79),there were 4 cases(7.8％)of local recurrence,12 cases(23.5％)of distant metastasis,and 5 cancer-related deaths(9.8％).Six months postoperatively,both the Wexner score and the low anterior resection syndrome(LARS)score significantly improved compared to post-nCRT values[Wexner:1(0-2)vs.2(1-5);LARS:3.3±5.75 vs.4.3±6.86;both P＜0.01].Conclusion:For patients with mid-to-low rectal cancer who achieve cCR or near-cCR after nCRT,local en bloc resection of the bowel wall lesions enables accurate assessment of residual tumor status and facilitates personalized subsequent treatment,potentially sparing some patients from radical surgery.Local resection can be a viable anus-preserving option for patients who are unfit for or strongly averse to radical resection.However,local excision cannot replace radical surgery,and its precise indications warrant further investigation.

Objective:To compare the prognostic impact of complete mesocolic excision (CME) versus D2 lymphadenectomy in patients with stage III right-sided colon cancer.Methods:A retrospective cohort study was conducted. Clinical data of 263 patients with stage III colon cancer undergoing right hemicolectomy in the Division of Colorectal Surgery, Department of General Surgery, Peking Union Medical College Hospital (January 1, 2016 to August 8, 2023) were included. Of the 263 patients, 152 underwent CME and 111 received D2 dissection. Propensity score matching (PSM) was employed to balance baseline characteristics between the two groups. Continuous variables were compared using the Mann-Whitney U test or Student's t-test; categorical variables were compared using the χ2 test or Fisher exact test. Survival curves were constructed using the Kaplan-Meier method, and the Log-Rank test was used to compare disease-free survival (DFS) and overall survival (OS) between groups. Cox proportional hazards models were utilized to analyze prognostic factors, with subgroup analyses performed.Results:Patients undergoing CME surgery were younger (proportion >75 years: 4.6% vs. 25.2%, P<0.001), had a lower burden of comorbidities (Charlson comorbidity index ≥ 1: 25.0% vs. 36.9%, P=0.045), The rates of open surgery and converted open surgery were lower [0.6% (1/152) vs. 4.5% (5/111) and 0.6% (1/152) vs. 2.7% (3/111), respectively; P=0.040].They also had a higher rate of receiving adjuvant therapy (92.7% vs. 76.0%, P<0.001). In terms of short-term postoperative outcomes, the CME group had a greater number of harvested lymph nodes (median: 30 vs. 25, P<0.001) and less blood loss (median: 20 ml vs. 20 ml, P=0.041). There were no significant differences between the groups in terms of the number of metastatic lymph nodes, operation time, and the incidence of postoperative complications. Survival analysis demonstrated significantly longer DFS in the CME group both before and after PSM. CME was an independent favorable prognostic factor for DFS (pre-PSM: HR=0.53, 95%CI: 0.31-0.91, P=0.022; post-PSM: HR=0.50, 95%CI: 0.26-0.97, P=0.042). No significant difference in OS was detected between the two groups across models. The subgroup analysis based on clinicopathological features revealed DFS benefits associated with CME in patients with tumor deposits (HR=0.41, 95%CI: 0.18-0.94, P=0.035), moderately-to-well-differentiated adenocarcinoma(HR=0.48, 95%CI: 0.26-0.90, P=0.023), proficient mismatch repair tumors (HR=0.55, 95%CI: 0.32-0.94, P=0.030), and pN2 stage disease (HR=0.43, 95%CI: 0.19-0.95, P=0.036). Conclusion:An extended lymph node dissection, as exemplified by CME, may confer a DFS advantage in patients with stage III right-sided colon cancer, especially those exhibiting a substantial burden of lymph node metastases.

Objective:To detect the association of tumor circumferential involvement range (CIR) with neoadjuvant chemoradiotherapy (NCRT) efficacy and long-term survival outcomes in locally advanced rectal cancer (LARC) patients.Methods:Clinical data of 451 patients admitted to our hospital from January, 2018 to January, 2022 were retrospectively collected. According to the CIRs as determined by rectal magnetic resonance imaging, patients were divided into the High group (≥2/3 cycle, 270 patients) and the Low group (＜2/3 cycle, 181 patients). The primary outcome was three-year disease-free survival. The baseline characteristics, pathological features, and survival outcomes were compared.Results:Compared to patients in the Low group, patients in the High group exhibited significantly larger tumor vertical diameters [(4.7±1.7) vs. (3.6±1.4)cm, P＜0.001], higher rates of mrT4 stage (37.8% vs. 13.2%, P＜0.001), and higher rates of positive mesorectal fascia (54.1% vs. 29.8%, P＜0.001) and extramural vascular invasion (55.6% vs. 38.1%, P＜0.001). Patients in the High group were mainly pT3-4 stages (46.7% vs. 30.9%, P=0.002), with significantly lower rates of pathological complete response (22.2% vs. 33.1%, P=0.010) , poorer tumor regression grades (48.9% vs. 60.8%, P=0.013), and higher rates of positive peripheral nerve invasion (11.5% vs. 5.5%, P=0.031), as compared to patients in the Low group. The median follow-up time was 40 months. About 11 (2.4%) and 48 patients (10.6%) experienced tumor local recurrence and distant metastasis, respectively. The recurrence rates were 2.2% and 2.6%, and the distant metastasis rates were 7.7% and 12.6%, respectively, in the Low group and the High group, with no statistical significance ( P=0.957, P=0.096). The three-year disease-free survival in the High group was significantly lower than that in the Low group (84.4% vs. 92.4%, P=0.014). Conclusions:The CIR is closely related to tumor burden, which can judge tumor response to NCRT, and is negatively related to survival prognosis. For patients who have more than a 2/3 cycle of CIR, intensified or consolidated treatments may be required to improve survival outcomes.

Objective:To investigate the completion rate of tumor evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients in the national multicenter real-world database.Methods:The prospective real-world study was conducted. The clinicopathological data of 1 074 patients who underwent surgical treatment for mid and low rectal cancer in 47 national medical institutions, including Peking Union Medical College Hospital et al, from May 12,2023 to May 11,2024 were collected. Observation indicators: (1) clinical characteristics of patients with mid and low rectal cancer; (2) initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer; (3) initial imaging evaluation of patients with mid and low rectal cancer; (4) imaging evaluation after neoadjuvant therapy for patients with mid and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M( Q1, Q3). Count data were described as absoluter numbers and/or percentages. Results:(1) Clinical characteristics of patients with mid and low rectal cancer. Of the 1 074 patients, there were 713 males and 361 females, aged 63(56,70)years. The body mass index of 1 074 patients was 24(21,26)kg/m 2.For American Society of Anesthesiologists classification, there were 147 cases of stage Ⅰ, 641 cases of stage Ⅱ, 157 cases of stage Ⅲ, 2 cases of stage Ⅳ, and there were 127 cases missing data. (2) Initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer. Of the 1 074 patients, there were 787 cases (73.28%) undergoing complete colonoscopy, and there were only 197 cases (18.34%) undergoing immunohistochemical evaluation of all four mismatch repair proteins. (3) Initial imaging evaluation of patients with mid and low rectal cancer. Of the 1 074 patients, there were 842(78.40%) patients completing magnetic resonance imaging (MRI) or ultrasound evaluation, and there were 914(85.10%) patients completing chest, abdomen, and pelvis enhanced computed tomography (CT) evaluation. In the 149 patients completing rectal ultrasound evaluation, there were 122 cases (81.88%) comple-ting T staging evaluation, and there were 81 cases (54.36%) completing N staging evaluation. In the 808 patients completing rectal MRI evaluation, there were 708 cases (87.62%) completing T staging evaluation, and there were 590 cases (73.02%) completing N staging evaluation. (4) Imaging evalua-tion after neoadjuvant therapy for patients with mid and low rectal cancer. Of the 388 patients with neoadjuvant therapy, there were 332 patients (85.57%) completing MRI or ultrasound evaluation, and there were 327 patients (84.28%) completing chest, abdomen, and pelvis enhanced CT evalua-tion. In the 70 patients completing rectal ultrasound evaluation, there were 65 cases (92.86%) com-pleting T staging evaluation, and there were 49 cases (70.00%) completing N staging evaluation. In the 327 patients completing rectal MRI evaluation, there were 246 cases (75.23%) completing T staging, and there were 228 cases (69.72%) completing N staging evaluation. Conclusion:The com-pletion rate of tumor imaging evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients on a national scale is relatively good.

Background and Aims:For patients with mid-to-low rectal cancer who achieve clinical complete response(cCR)or near-cCR after neoadjuvant chemoradiotherapy(nCRT),the key concern for both clinicians and patients is how to preserve anal function as much as possible without significantly compromising oncological outcomes.This study was performed to evaluate the safety and feasibility of local excision as an anus-preserving approach in rectal cancer patients with cCR or near-cCR.Methods:A retrospective analysis was conducted on 51 patients with mid-to-low rectal cancer who underwent local resection after achieving cCR or near-cCR following nCRT at Peking Union Medical College Hospital,Chinese Academy of Medical Sciences,between March 2014 and July 2023.The clinical characteristics,imaging and pathological findings,surgical outcomes,as well as oncological and functional results were reviewed.Results:Among the 51 patients,34 were male and 17 were female,with a mean age of 61±14 years.Pre-nCRT imaging staging showed:cT1-2N0 in 12 cases(23.5％),cT3N0 in 13 cases(25.5％),cT1-3N0-1 in 19 cases(37.4％),and cT1-3N2 in 7 cases(13.7％).The average tumor distance from the anal verge was(4.5±1.1)cm.After achieving cCR or near-cCR following nCRT,all patients underwent local resection:40 cases(78.4％)underwent transanal endoscopic microsurgery(TEM),7 cases(13.7％)underwent transanal minimally invasive surgery(TAMIS),and 4 cases(7.8％)underwent conventional transanal local excision.The postoperative complication rate was 27.5％(14/51),with 71.4％classified as Clavien-Dindo grade Ⅰ.Postoperative histopathology showed ypT0 in 26 cases(51.0％),ypT1 in 8 cases(15.7％),ypT2 in 16 cases(31.4％),and ypT3 in 1 case(2.0％).The concordance rate between pathological results and preoperative imaging was 54.9％.Over a median follow-up of 60 months(range:34-79),there were 4 cases(7.8％)of local recurrence,12 cases(23.5％)of distant metastasis,and 5 cancer-related deaths(9.8％).Six months postoperatively,both the Wexner score and the low anterior resection syndrome(LARS)score significantly improved compared to post-nCRT values[Wexner:1(0-2)vs.2(1-5);LARS:3.3±5.75 vs.4.3±6.86;both P＜0.01].Conclusion:For patients with mid-to-low rectal cancer who achieve cCR or near-cCR after nCRT,local en bloc resection of the bowel wall lesions enables accurate assessment of residual tumor status and facilitates personalized subsequent treatment,potentially sparing some patients from radical surgery.Local resection can be a viable anus-preserving option for patients who are unfit for or strongly averse to radical resection.However,local excision cannot replace radical surgery,and its precise indications warrant further investigation.

Objective:To analyze the types and characteristics of post-operative complications in colorectal cancer patients aged over 85 years undergoing laparoscopic surgery, and to summarize peri-operative management strategies.Methods:This was an observational study. Inclusion criteria: pathologically confirmed adenocarcinoma; tumor located in ileocecum, ascending colon, transverse colon, descending colon, sigmoid colon, or rectum; undergoing laparoscopic radical resection for colorectal cancer; complete clinical data. Exclusion criteria included distant metastasis, synchronous resection of multiple primary cancers, simultaneous liver metastasis surgery, and follow-up duration <1 month. A retrospective analysis was conducted on 191 patients of colorectal cancer patients aged over 85 years who underwent laparoscopic radical surgery in the General Surgery Department at Peking Union Medical College Hospital from January 2019 to January 2024. Among 191 patients, 107 patients (56.0%) had colon cancer and 84 (44.0%) rectal cancer. All patients received "home-based prehabilitation" and post-operative "enhanced recovery after surgery" protocols. Patient characteristics, peri-operative complication types, treatments, and outcomes were analyzed.Results:Post-operative complications occurred in 97 patients (50.8%), including 53 colon cancer patients (54.6%) and 44 rectal cancer patients (45.4%). Comorbidities existed in 88 patients (90.7%), with 93 patients (95.9%) classified as ASA II-III pre-operatively and 86 (88.7%) having nutritional risks. Surgical procedures included Dixon procedure (38 patients, 39.2%), right hemicolectomy (33 patients, 34.0%), sigmoidectomy (10 patients, 10.3%), and 17 patients (17.5%) received prophylactic stomas. Complication types comprised non-anastomotic infections (38 patients, 19.9%), intestinal flora disorder (26 patients, 13.6%), anastomotic/wound/stoma-related complications (16 patients, 8.4%), thrombotic/hemorrhagic events (6 patients, 3.1%), and others (11 patients, 5.8%). By Clavien-Dindo classification: Grade I (12 patients, 6.3%), Grade II (69 patients, 36.1%), Grade III (12 patients, 6.3%), and Grade IV (4 patients, 2.1%). Except for 5 patients (2.6%) requiring unplanned re-operation, all complications resolved with conservative treatment. The median duration of post-operative hospitalization was 9.5 days (7–13).Conclusion:Non-anastomotic infections and intestinal flora disorder constitute predominant complications after laparoscopic surgery in colorectal cancer patients aged over 85 years, mostly manageable with conservative treatment. Strengthened peri-operative management incorporating pre-operative prehabilitation and post-operative enhanced recovery after surgery protocols is crucial for patients aged over 85 years.

Objective:To investigate the completion rate of tumor evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients in the national multicenter real-world database.Methods:The prospective real-world study was conducted. The clinicopathological data of 1 074 patients who underwent surgical treatment for mid and low rectal cancer in 47 national medical institutions, including Peking Union Medical College Hospital et al, from May 12,2023 to May 11,2024 were collected. Observation indicators: (1) clinical characteristics of patients with mid and low rectal cancer; (2) initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer; (3) initial imaging evaluation of patients with mid and low rectal cancer; (4) imaging evaluation after neoadjuvant therapy for patients with mid and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M( Q1, Q3). Count data were described as absoluter numbers and/or percentages. Results:(1) Clinical characteristics of patients with mid and low rectal cancer. Of the 1 074 patients, there were 713 males and 361 females, aged 63(56,70)years. The body mass index of 1 074 patients was 24(21,26)kg/m 2.For American Society of Anesthesiologists classification, there were 147 cases of stage Ⅰ, 641 cases of stage Ⅱ, 157 cases of stage Ⅲ, 2 cases of stage Ⅳ, and there were 127 cases missing data. (2) Initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer. Of the 1 074 patients, there were 787 cases (73.28%) undergoing complete colonoscopy, and there were only 197 cases (18.34%) undergoing immunohistochemical evaluation of all four mismatch repair proteins. (3) Initial imaging evaluation of patients with mid and low rectal cancer. Of the 1 074 patients, there were 842(78.40%) patients completing magnetic resonance imaging (MRI) or ultrasound evaluation, and there were 914(85.10%) patients completing chest, abdomen, and pelvis enhanced computed tomography (CT) evaluation. In the 149 patients completing rectal ultrasound evaluation, there were 122 cases (81.88%) comple-ting T staging evaluation, and there were 81 cases (54.36%) completing N staging evaluation. In the 808 patients completing rectal MRI evaluation, there were 708 cases (87.62%) completing T staging evaluation, and there were 590 cases (73.02%) completing N staging evaluation. (4) Imaging evalua-tion after neoadjuvant therapy for patients with mid and low rectal cancer. Of the 388 patients with neoadjuvant therapy, there were 332 patients (85.57%) completing MRI or ultrasound evaluation, and there were 327 patients (84.28%) completing chest, abdomen, and pelvis enhanced CT evalua-tion. In the 70 patients completing rectal ultrasound evaluation, there were 65 cases (92.86%) com-pleting T staging evaluation, and there were 49 cases (70.00%) completing N staging evaluation. In the 327 patients completing rectal MRI evaluation, there were 246 cases (75.23%) completing T staging, and there were 228 cases (69.72%) completing N staging evaluation. Conclusion:The com-pletion rate of tumor imaging evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients on a national scale is relatively good.

Objective:To compare the prognostic impact of complete mesocolic excision (CME) versus D2 lymphadenectomy in patients with stage III right-sided colon cancer.Methods:A retrospective cohort study was conducted. Clinical data of 263 patients with stage III colon cancer undergoing right hemicolectomy in the Division of Colorectal Surgery, Department of General Surgery, Peking Union Medical College Hospital (January 1, 2016 to August 8, 2023) were included. Of the 263 patients, 152 underwent CME and 111 received D2 dissection. Propensity score matching (PSM) was employed to balance baseline characteristics between the two groups. Continuous variables were compared using the Mann-Whitney U test or Student's t-test; categorical variables were compared using the χ2 test or Fisher exact test. Survival curves were constructed using the Kaplan-Meier method, and the Log-Rank test was used to compare disease-free survival (DFS) and overall survival (OS) between groups. Cox proportional hazards models were utilized to analyze prognostic factors, with subgroup analyses performed.Results:Patients undergoing CME surgery were younger (proportion >75 years: 4.6% vs. 25.2%, P<0.001), had a lower burden of comorbidities (Charlson comorbidity index ≥ 1: 25.0% vs. 36.9%, P=0.045), The rates of open surgery and converted open surgery were lower [0.6% (1/152) vs. 4.5% (5/111) and 0.6% (1/152) vs. 2.7% (3/111), respectively; P=0.040].They also had a higher rate of receiving adjuvant therapy (92.7% vs. 76.0%, P<0.001). In terms of short-term postoperative outcomes, the CME group had a greater number of harvested lymph nodes (median: 30 vs. 25, P<0.001) and less blood loss (median: 20 ml vs. 20 ml, P=0.041). There were no significant differences between the groups in terms of the number of metastatic lymph nodes, operation time, and the incidence of postoperative complications. Survival analysis demonstrated significantly longer DFS in the CME group both before and after PSM. CME was an independent favorable prognostic factor for DFS (pre-PSM: HR=0.53, 95%CI: 0.31-0.91, P=0.022; post-PSM: HR=0.50, 95%CI: 0.26-0.97, P=0.042). No significant difference in OS was detected between the two groups across models. The subgroup analysis based on clinicopathological features revealed DFS benefits associated with CME in patients with tumor deposits (HR=0.41, 95%CI: 0.18-0.94, P=0.035), moderately-to-well-differentiated adenocarcinoma(HR=0.48, 95%CI: 0.26-0.90, P=0.023), proficient mismatch repair tumors (HR=0.55, 95%CI: 0.32-0.94, P=0.030), and pN2 stage disease (HR=0.43, 95%CI: 0.19-0.95, P=0.036). Conclusion:An extended lymph node dissection, as exemplified by CME, may confer a DFS advantage in patients with stage III right-sided colon cancer, especially those exhibiting a substantial burden of lymph node metastases.