Objective To investigate the predictive value of the combined tumor burden score (TBS) and platelet-albumin-bilirubin (PALBI) score model for postoperative tumor recurrence in liver transplant recipients with hepatocellular carcinoma (HCC). Methods The general information of 158 recipients diagnosed with HCC and underwent liver transplantation at the 900th Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army from 2008 to 2021 was collected. Lasso regression analysis combined with multivariate Cox regression analysis were used to identify independent risk factors for postoperative tumor recurrence after liver transplantation with HCC. A nomogram prediction model was constructed based on variables selected by Lasso regression analysis, and the predictive performance of the model was verified by calibration curve and clinical decision curve. The optimal cut-off values for postoperative tumor recurrence in liver transplant recipients with HCC were determined by receiver operating characteristic (ROC) curve, and Kaplan-Meier analysis was used to compare survival differences among different groups. Results Among the 158 liver transplant recipients with HCC, 82 experienced tumor recurrence, with a recurrence rate of 51.9% and a median tumor-free survival time of 10 (4, 25) months. Results of Lasso regression analysis and multivariate Cox regression analysis showed that alpha-fetoprotein (AFP) ≥400 ng/mL, TBS and PALBI score were all independent risk factors for postoperative tumor recurrence in liver transplant recipients with HCC (all P<0.05). The combined high TBS-high PALBI score showed the highest predictive value (hazard ratio 6.909, 95% confidence interval 3.067-15.563, P<0.001). A nomogram prediction model was constructed based on six variables selected by Lasso regression analysis. Calibration curve showed good consistency between the model's predicted results and the ideal curve. Decision curve analysis indicated that the nomogram prediction model provided the highest clinical benefit for predicting 1-year tumor-free survival after liver transplantation with HCC. Time-dependent ROC curves at 1, 3 and 5 years after surgery showed that TBS-PALBI model had good predictive performance, with no significant difference in area under the curve (AUC) compared with TBS-PALBI-AFP model. The optimal cut-off values for predicting postoperative tumor recurrence were determined by ROC curve, with a PALBI score cut-off of −2.334 and a TBS cut-off of 5.305. Recipients were divided into a low TBS-low PALBI score group (n=47) and a low/high TBS-low/high PALBI score group (at least one score was high) (n=111). Kaplan-Meier survival analysis showed that the low TBS-low PALBI score group had a higher tumor-free survival rate than the low/high TBS-low/high PALBI score group, with a significant difference (P<0.05). Conclusions TBS-PALBI model provides a novel, simple and effective tool for assessing the prognosis of liver transplant recipients with HCC. The nomogram model constructed based on this has significant advantages in predictive performance and may serve as a reference for guiding individualized treatment plans and improving clinical outcomes.

Objective To investigate the mutation types of colorectal neuroendocrine tumors(NETs)and better un-derstand the pathogenesis of colorectal nets.Methods Patients undergoing colorectal NETs surgery were recruited,colorectal NETs and corresponding adjacent cancerous tissues were collected,and whole genome sequencing(WGS)was performed and further deeply analyzed.Results WGS sequencing showed that the mutation types of colorectal NETs included single nucleotide mutations,insertion and deletion mutations(InDel,less than 50 bp in length),copy number variations(CNV),and large structural variations(SV,more than 50 bp in length),such as insertion(INS),deletion(DEL),intra chromosomal translocation(ITX),inter chromosomal translocation(CTX)and inversion(INV).Conclusions A large number of somatic mutations occur in colorectal NETs,especially chro-mosome translocation

Objective:To investigate the interactive effect of mismatch repair (MMR) protein status and adverse clinicopathological features on prognosis of stage Ⅰ-Ⅲ colon cancer.Methods:The retrospective cohort study was conducted. The clinicopathological data of 1 650 patients with colon cancer of stage Ⅰ-Ⅲ who were admitted to 7 hospitals in China from January 2016 to December 2017 were collected. There were 963 males and 687 females, aged 62(53,71)years. Patients were classified as 230 cases of MMR deficiency (dMMR) and 1 420 cases of MMR proficiency (pMMR) based on their MMR protein status. Observation indicators: (1) comparison of clinicopathological characteristics between patients of different MMR protein status; (2) analysis of factors affecting the survival outcomes of patients of dMMR; (3) analysis of factors affecting the survival outcomes of patients of pMMR; (4) interaction analysis of MMR and adverse clinicopathological features on survival outcomes. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Comparison of ordinal data was conducted using the Mann-Whitney U test. The random forest interpolation method was used for missing values in data interpolation. Univariate analysis was conducted using the COX proportional risk regression model, and multivariate analysis was conducted using the COX stepwise regression with forward method. The coefficient of multiplication interaction effect was obtained using the interaction term coefficient of COX proportional risk regression model. Evaluation of additive interaction effects was conducted using the relative excess risk due to interaction ( RERI). Results:(1) Comparison of clinicopathological characteristics between patients of different MMR protein status. There were significant differences in age, T staging, the number of lymph node harvest, the number of lymph node harvest <12, high grade tumor between patients of dMMR and pMMR ( P<0.05). (2) Analysis of factors affecting the survival outcomes of patients of dMMR. Results of multivariate analysis showed that T staging, N staging, the number of lymph node harvest <12 were independent factors affecting the disease-free survival (DFS) of colon cancer patients of dMMR ( hazard ratio=3.548, 2.589, 6.702, 95% confidence interval as 1.460-8.620, 1.064-6.301, 1.886-23.813, P<0.05). Age and N staging were independent factors affecting the overall survival (OS) of colon cancer patients of dMMR ( hazard ratio=1.073, 10.684, 95% confidence interval as 1.021-1.126, 2.311-49.404, P<0.05). (3) Analysis of factors affecting the survival outcomes of patients of pMMR. Results of multivariate analysis showed that age, T staging, N staging, vascular tumor thrombus were independent factors affecting the DFS of colon cancer patients of pMMR ( hazard ratio=1.018, 2.214, 2.598, 1.549, 95% confidence interval as 1.006-1.030, 1.618-3.030, 1.921-3.513, 1.118-2.147, P<0.05). Age, T staging, N staging, high grade tumor were independent factors affecting the OS of colon cancer patients of pMMR ( hazard ratio=1.036, 2.080, 2.591, 1.615, 95% confidence interval as 1.020-1.052, 1.407-3.075, 1.791-3.748, 1.114-2.341, P<0.05). (4) Interaction analysis of MMR and adverse clinicopathological features on survival outcomes. Results of interaction analysis showed that the multiplication interaction effect between the number of lymph node harvest <12 and MMR protein status was significant on DFS of colon cancer patients ( hazard ratio=3.923, 95% confidence interval as 1.057-14.555, P<0.05). The additive interaction effects between age and MMR protein status, between high grade tumor and MMR protein status were significant on OS of colon cancer patients ( RERI=-0.033, -1.304, 95% confidence interval as -0.049 to -0.018, -2.462 to -0.146). Conclusions:There is an interaction between the MMR protein status and the adverse clinicopathological features (the number of lymph node harvest <12, high grade tumor) on prognosis of colon cancer patients of stage Ⅰ-Ⅲ. In patients of dMMR, the number of lymph node harvest <12 has a stronger predictive effect on poor prognosis. In patients of pMMR, the high grade tumor has a stronger predictive effect on poor prognosis.

Objective:The aim of this study was to evaluate the impact of neoadjuvant radiotherapy on anorectal function of patients with mid-low rectal cancer by means of high-resolution anorectal manometry.Methods:A retrospective observational study was conducted. Information on patients with mid-low rectal cancer was collected from the prospective registry database of Rectal Cancer at Peking Union Medical College Hospital (PUMCH) from June 2020 to April 2023. Anorectal functions were detected using three-dimensional high-resolution manometry system. Logistic regression analysis was performed to identify the factors associated with the changed anorectal manometry.Results:A total of 45 patients with mid-low rectal cancer were included in the study. Thirty-two (71.1%) patients were male, 13 (28.9%) patients were female. The mean age was 60±11 years, and the mean BMI was 23.4±3.7 kg/m 2. The mean distance between the lower edge of the tumor and the anal verge was 5.4±1.5 cm. The median size of the tumor was 3.4 (2.9-4.5) cm, and the median circumferential extent of the tumor was 66.0 (45.5-75.0) %. 41 (81.1%) patients were MRI T3-4 and 40 (88.9%) patients were MRI N positive. The resting pressure has a decreasing trend after neoadjuvant radiotherapy (55.3±32.0 mmHg vs. 48.0±28.5 mmHg, t=1.930, P=0.060). There was no significant change in maximum squeezing and the length of the high-pressure zone after neoadjuvant radiotherapy. All volumes describing rectal sensitivity (first sensation, desire to defecate, and maximum tolerance) were lower after neoadjuvant radiotherapy. And maximum tolerance was significantly lower (66.0 [49.0,88.0] ml vs. 52.0 [39.0,73.5] ml, Z=-2.481, P=0.013). Univariate analysis demonstrated that the downstage of N-stage was associated with the decrease in maximum tolerance (OR=6.533, 95%CI:1.254-34.051, P=0.026). Conclusion:Neoadjuvant radiotherapy damages anorectal function by decreasing the resting pressure and rectal sensory threshold of patients. The N-stage downstaging was associated with a decrease in maximum tolerance.

Objective:To analyze the differences in clinicopathological features of colon cancers and survival between patients with right- versus left-sided colon cancers.Methods:This was a retrospective cohort study. Information on patients with colon cancer from January 2016 to August 2020 was collected from the prospective registry database at Peking Union Medical College Hospital . Primary tumors located in the cecum, ascending colon, and proximal two‐thirds of the transverse colon were defined as right-sided colon cancers (RCCs), whereas primary tumors located in the distal third of the transverse colon, descending colon, or sigmoid colon were defined as left‐sided colon cancers (LCCs). Clinicopathological features were compared using the χ 2 test or Mann‐Whitney U test. Survival was estimated by Kaplan‐Meier curves and the log‐rank test. Factors that differed significantly between the two groups were identified by multivariate survival analyses performed with the Cox proportional hazards function. One propensity score matching was performed to eliminate the effects of confounding factors. Results:The study cohort comprised 856 patients, with TNM Stage I disease, 391 (45.7%) with Stage II, and 336 (39.3%) with Stage III, including 442 (51.6%) with LCC and 414 (48.4%) with RCC and 129 (15.1%). Defective mismatch repair (dMMR) was identified in 139 patients (16.2%). Compared with RCC, the proportion of men (274/442 [62.0%] vs. 224/414 [54.1%], χ 2=5.462, P=0.019), body mass index (24.2 [21.9, 26.6] kg/m 2 vs. 23.2 [21.3, 25.5] kg/m 2, U=78,789.0, P<0.001), and well/moderately differentiated cancer (412/442 [93.2%] vs. 344/414 [83.1%], χ 2=22.266, P<0.001) were higher in the LCC than the RCC group. In contrast, the proportion of dMMR (40/442 [9.0%] vs. 99/414 [23.9%], χ 2=34.721, P<0.001) and combined vascular invasion (106/442[24.0%] vs. 125/414[30.2%], χ 2=4.186, P=0.041) were lower in the LCC than RCC group. The median follow‐up time for all patients was 48 (range 33, 59) months. The log‐rank test revealed no significant differences in disease-free survival (DFS) ( P=0.668) or overall survival (OS) ( P=0.828) between patients with LCC versus RCC. Cox proportional hazards model showed that dMMR was significantly associated with a longer DFS (HR=0.419, 95%CI: 0.204?0.862, P=0.018), whereas a higher proportion of T3‐4 (HR=2.178, 95%CI: 1.089?4.359, P=0.028), N+ (HR=2.126, 95%CI: 1.443?3.133, P<0.001), and perineural invasion (HR=1.835, 95%CI: 1.115?3.020, P=0.017) were associated with poor DFS. Tumor location was not associated with DFS or OS (all P>0.05). Subsequent analysis showed that RCC patients with dMMR had longer DFS than did RCC patients with pMMR (HR=0.338, 95%CI: 0.146?0.786, P=0.012). However, the difference in OS between the two groups was not statistically significant (HR=0.340, 95%CI:0.103?1.119, P=0.076). After propensity score matching for independent risk factors for DFS, the log‐rank test revealed no significant differences in DFS ( P=0.343) or OS ( P=0.658) between patients with LCC versus RCC, whereas patient with dMMR had better DFS ( P=0.047) and OS ( P=0.040) than did patients with pMMR. Conclusions:Tumor location is associated with differences in clinicopathological features; however, this has no impact on survival. dMMR status is significantly associated with longer survival: this association may be stronger in RCC patients.

Objective:To explore the impact on safety and prognosis in patients with right-sided colon cancer participating in surgical clinical research.Methods:This retrospective cohort study utilized data from a randomized controlled trial (RELARC study) conducted by the colorectal surgery group at Peking Union Medical College Hospital in which laparoscopic complete mesocolic excision (CME) was compared with D2 radical resection for the management of right-sided colon cancer. The eligibility criteria were age 18–75 years, biopsy-proven colon adenocarcinoma, tumor located between the cecum and right 1/3 of the transverse colon, enhanced chest, abdomen, and pelvic CT scans suggesting tumor stage T2–T4N0M0 or TanyN+ M0, and having undergone radical surgical treatment from January 2016 to December 2019. Exclusion factors included multiple primary colorectal cancers, preoperative stage T1N0 or enlarged central lymph nodes, tumor involving surrounding organs requiring their resection, definite distant metastasis or otherwise unable to undergo R0 resection, history of any other malignant tumors within previous 5 years, intestinal obstruction, perforation, or gastrointestinal bleeding requiring emergency surgery, and assessed as unsuitable for laparoscopic surgery. Patients who had participated in the RELARC study were included in the RELARC group, whereas those who met the inclusion criteria but refused to participate in the RELAEC study were included in the control group. The main indicators studied were the patient's baseline data, surgery and perioperative conditions, pathological characteristics, adjuvant treatment, and postoperative follow-up (including average frequency of follow-up within the first 3 years) and survival (including 3-year disease-free survival rate (DFS) and 3-year overall survival rate (OS). Differences in these indicators between the RELARC and control groups were compared.Results:The study cohort comprised 290 patients, 173 in the RELARC group (RELARC-CME group, 82; RELARC-D2 group, 91) and 117 in the control group (CME control group, 72; D2 control group, 45). There was a significantly higher proportion of overweight patients (BMI ≥24 kg/m 2) in the RELARC-CME than in the CME control group (67.1% [55/82] vs. 33.3% [24/72], χ 2=17.469, P<0.001). There were no other statistically significant differences in baseline characteristics (all P>0.05). No significant disparities were found between the CME and D2 groups in terms of operation duration, intraoperative blood loss, rate of conversion to open surgery, combined organ resection, intraoperative blood transfusion, or intraoperative complications (all P>0.05). There was a trend toward Clavien–Dindo grade II or higher postoperative complications in the RELARC-CME group (24.4% [20/82]) than in the CME control group (18.1% [13/72]); however, this difference was not statistically significant (χ 2=0.914, P=0.339). Similarly, the difference in this rate did not differ significantly between the RELARC-D2 group (25.3% [23/91]) and D2 control group (24.4% [11/45], χ 2=0.011, P=0.916). The median duration of postoperative follow-up was significantly shorter in the RELARC groups than in the corresponding control groups. Specifically, the median duration of follow-up was 4.5 (4.5, 4.5) months in the RELARC-CME and 7.2 (6.0, 9.0) months in the CME control group ( Z=-10.608, P<0.001). Similarly, the median duration of follow-up was 4.5 (4.5, 4.5) months in the RELARC-D2 group as opposed to 8.3 (6.6, 9.0) months in the D2 control group ( Z=-10.595, P<0.001). The 3-year DFS rate (91.5%) and OS rate (96.3%) tended to be higher in the RELARC-CME group than in the CME control group (84.7% and 90.3%, respectively). The 3-year DFS rate (87.9%) and OS rate (96.7%) tended to be higher in the RELARC-D2 group than in the D2 control group (81.8% and 88.6%, respectively); however, these differences were not statistically significant (all P>0.05). Subgroup analysis according to pathological stage revealed that patients in the RELARC-D2 group with pN0 stage achieved a significantly superior 3-year OS rate than did those in the D2 control group (100% vs. 88.9%, P=0.008). We identified no statistically significant differences in survival rates between the remaining subgroups (all P>0.05). Conclusions:A high-quality surgical clinical trial with close follow-up can achieve perioperative safety and a trend toward improved survival outcomes.

Objective:To investigate the clinical characteristics of brain metastases after radical surgery for locally advanced rectal cancer (LARC).Methods:The clinical characteristics of LARC with brain metastases treated in the Department of General Surgery, Peking Union Medical College Hospital from 2013 to 2023 were retrospectively analyzed. The inclusion criteria were rectal adenocarcinoma within 15 cm of the anal verge and having undergone radical surgery, and the exclusion criterion was primary malignant tumor of the brain. The main outcomes were overall survival (OS), disease-free survival (DFS), and disease-specific overall survival (determined as the interval between occurrence of brain metastasis to death from any causes). The Kaplan–Meier method was used for survival analysis.Results:We identified 4500 patients with LARC, 20 (0.4%) of whom had brain metastases. The mean age of patients with brain metastases was 63.8±9.3 years. They comprised five women and 15 men. The brain was the first site of metastasis in four patients (20%) whereas 18 patients had heterochronous extracranial metastases before brain metastasis. Two patients also had multi-organ metastases. The most common manifestations of brain metastases were dizziness and headache (five patients, 25%), sudden onset of limb weakness (four, 20%), sudden speech impairment (two, 10%), and polyopia (two, 10%). The metastases were diagnosed during follow-up in three patients (15%). Four of the patients were asymptomatic (20%). Treatment approaches included surgical resection (six patients, 30%), chemoradiotherapy (nine, 45%), and palliative (five, 25%). The median follow-up time was 45.5 (4–112) months until October 2023. 1y-OS, 3y-OS, and 5y-OS were 95.0%, 62.9%, and 43.3%, respectively. 1y-DFS, 3y-DFS, and 5y-DFS were 55.0%, 25.0%, and 5.0%, respectively. With brain metastasis as the starting point, the median duration of survival was 16 (10.2–21.8) months.Conclusion:The incidence of brain metastasis is relatively low in patients with LARC, who often have multiple synchronous extracranial metastases. Brain metastases lack specific manifestations and more often occur in male patients. Surgical intervention or combined radiotherapy and chemotherapy may improve disease-specific survival to a certain extent. However, the overall prognosis remains poor.

Objective:The aim of this study was to evaluate the impact of neoadjuvant radiotherapy on anorectal function of patients with mid-low rectal cancer by means of high-resolution anorectal manometry.Methods:A retrospective observational study was conducted. Information on patients with mid-low rectal cancer was collected from the prospective registry database of Rectal Cancer at Peking Union Medical College Hospital (PUMCH) from June 2020 to April 2023. Anorectal functions were detected using three-dimensional high-resolution manometry system. Logistic regression analysis was performed to identify the factors associated with the changed anorectal manometry.Results:A total of 45 patients with mid-low rectal cancer were included in the study. Thirty-two (71.1%) patients were male, 13 (28.9%) patients were female. The mean age was 60±11 years, and the mean BMI was 23.4±3.7 kg/m 2. The mean distance between the lower edge of the tumor and the anal verge was 5.4±1.5 cm. The median size of the tumor was 3.4 (2.9-4.5) cm, and the median circumferential extent of the tumor was 66.0 (45.5-75.0) %. 41 (81.1%) patients were MRI T3-4 and 40 (88.9%) patients were MRI N positive. The resting pressure has a decreasing trend after neoadjuvant radiotherapy (55.3±32.0 mmHg vs. 48.0±28.5 mmHg, t=1.930, P=0.060). There was no significant change in maximum squeezing and the length of the high-pressure zone after neoadjuvant radiotherapy. All volumes describing rectal sensitivity (first sensation, desire to defecate, and maximum tolerance) were lower after neoadjuvant radiotherapy. And maximum tolerance was significantly lower (66.0 [49.0,88.0] ml vs. 52.0 [39.0,73.5] ml, Z=-2.481, P=0.013). Univariate analysis demonstrated that the downstage of N-stage was associated with the decrease in maximum tolerance (OR=6.533, 95%CI:1.254-34.051, P=0.026). Conclusion:Neoadjuvant radiotherapy damages anorectal function by decreasing the resting pressure and rectal sensory threshold of patients. The N-stage downstaging was associated with a decrease in maximum tolerance.

Objective:To analyze the differences in clinicopathological features of colon cancers and survival between patients with right- versus left-sided colon cancers.Methods:This was a retrospective cohort study. Information on patients with colon cancer from January 2016 to August 2020 was collected from the prospective registry database at Peking Union Medical College Hospital . Primary tumors located in the cecum, ascending colon, and proximal two‐thirds of the transverse colon were defined as right-sided colon cancers (RCCs), whereas primary tumors located in the distal third of the transverse colon, descending colon, or sigmoid colon were defined as left‐sided colon cancers (LCCs). Clinicopathological features were compared using the χ 2 test or Mann‐Whitney U test. Survival was estimated by Kaplan‐Meier curves and the log‐rank test. Factors that differed significantly between the two groups were identified by multivariate survival analyses performed with the Cox proportional hazards function. One propensity score matching was performed to eliminate the effects of confounding factors. Results:The study cohort comprised 856 patients, with TNM Stage I disease, 391 (45.7%) with Stage II, and 336 (39.3%) with Stage III, including 442 (51.6%) with LCC and 414 (48.4%) with RCC and 129 (15.1%). Defective mismatch repair (dMMR) was identified in 139 patients (16.2%). Compared with RCC, the proportion of men (274/442 [62.0%] vs. 224/414 [54.1%], χ 2=5.462, P=0.019), body mass index (24.2 [21.9, 26.6] kg/m 2 vs. 23.2 [21.3, 25.5] kg/m 2, U=78,789.0, P<0.001), and well/moderately differentiated cancer (412/442 [93.2%] vs. 344/414 [83.1%], χ 2=22.266, P<0.001) were higher in the LCC than the RCC group. In contrast, the proportion of dMMR (40/442 [9.0%] vs. 99/414 [23.9%], χ 2=34.721, P<0.001) and combined vascular invasion (106/442[24.0%] vs. 125/414[30.2%], χ 2=4.186, P=0.041) were lower in the LCC than RCC group. The median follow‐up time for all patients was 48 (range 33, 59) months. The log‐rank test revealed no significant differences in disease-free survival (DFS) ( P=0.668) or overall survival (OS) ( P=0.828) between patients with LCC versus RCC. Cox proportional hazards model showed that dMMR was significantly associated with a longer DFS (HR=0.419, 95%CI: 0.204?0.862, P=0.018), whereas a higher proportion of T3‐4 (HR=2.178, 95%CI: 1.089?4.359, P=0.028), N+ (HR=2.126, 95%CI: 1.443?3.133, P<0.001), and perineural invasion (HR=1.835, 95%CI: 1.115?3.020, P=0.017) were associated with poor DFS. Tumor location was not associated with DFS or OS (all P>0.05). Subsequent analysis showed that RCC patients with dMMR had longer DFS than did RCC patients with pMMR (HR=0.338, 95%CI: 0.146?0.786, P=0.012). However, the difference in OS between the two groups was not statistically significant (HR=0.340, 95%CI:0.103?1.119, P=0.076). After propensity score matching for independent risk factors for DFS, the log‐rank test revealed no significant differences in DFS ( P=0.343) or OS ( P=0.658) between patients with LCC versus RCC, whereas patient with dMMR had better DFS ( P=0.047) and OS ( P=0.040) than did patients with pMMR. Conclusions:Tumor location is associated with differences in clinicopathological features; however, this has no impact on survival. dMMR status is significantly associated with longer survival: this association may be stronger in RCC patients.

Objective:To explore the impact on safety and prognosis in patients with right-sided colon cancer participating in surgical clinical research.Methods:This retrospective cohort study utilized data from a randomized controlled trial (RELARC study) conducted by the colorectal surgery group at Peking Union Medical College Hospital in which laparoscopic complete mesocolic excision (CME) was compared with D2 radical resection for the management of right-sided colon cancer. The eligibility criteria were age 18–75 years, biopsy-proven colon adenocarcinoma, tumor located between the cecum and right 1/3 of the transverse colon, enhanced chest, abdomen, and pelvic CT scans suggesting tumor stage T2–T4N0M0 or TanyN+ M0, and having undergone radical surgical treatment from January 2016 to December 2019. Exclusion factors included multiple primary colorectal cancers, preoperative stage T1N0 or enlarged central lymph nodes, tumor involving surrounding organs requiring their resection, definite distant metastasis or otherwise unable to undergo R0 resection, history of any other malignant tumors within previous 5 years, intestinal obstruction, perforation, or gastrointestinal bleeding requiring emergency surgery, and assessed as unsuitable for laparoscopic surgery. Patients who had participated in the RELARC study were included in the RELARC group, whereas those who met the inclusion criteria but refused to participate in the RELAEC study were included in the control group. The main indicators studied were the patient's baseline data, surgery and perioperative conditions, pathological characteristics, adjuvant treatment, and postoperative follow-up (including average frequency of follow-up within the first 3 years) and survival (including 3-year disease-free survival rate (DFS) and 3-year overall survival rate (OS). Differences in these indicators between the RELARC and control groups were compared.Results:The study cohort comprised 290 patients, 173 in the RELARC group (RELARC-CME group, 82; RELARC-D2 group, 91) and 117 in the control group (CME control group, 72; D2 control group, 45). There was a significantly higher proportion of overweight patients (BMI ≥24 kg/m 2) in the RELARC-CME than in the CME control group (67.1% [55/82] vs. 33.3% [24/72], χ 2=17.469, P<0.001). There were no other statistically significant differences in baseline characteristics (all P>0.05). No significant disparities were found between the CME and D2 groups in terms of operation duration, intraoperative blood loss, rate of conversion to open surgery, combined organ resection, intraoperative blood transfusion, or intraoperative complications (all P>0.05). There was a trend toward Clavien–Dindo grade II or higher postoperative complications in the RELARC-CME group (24.4% [20/82]) than in the CME control group (18.1% [13/72]); however, this difference was not statistically significant (χ 2=0.914, P=0.339). Similarly, the difference in this rate did not differ significantly between the RELARC-D2 group (25.3% [23/91]) and D2 control group (24.4% [11/45], χ 2=0.011, P=0.916). The median duration of postoperative follow-up was significantly shorter in the RELARC groups than in the corresponding control groups. Specifically, the median duration of follow-up was 4.5 (4.5, 4.5) months in the RELARC-CME and 7.2 (6.0, 9.0) months in the CME control group ( Z=-10.608, P<0.001). Similarly, the median duration of follow-up was 4.5 (4.5, 4.5) months in the RELARC-D2 group as opposed to 8.3 (6.6, 9.0) months in the D2 control group ( Z=-10.595, P<0.001). The 3-year DFS rate (91.5%) and OS rate (96.3%) tended to be higher in the RELARC-CME group than in the CME control group (84.7% and 90.3%, respectively). The 3-year DFS rate (87.9%) and OS rate (96.7%) tended to be higher in the RELARC-D2 group than in the D2 control group (81.8% and 88.6%, respectively); however, these differences were not statistically significant (all P>0.05). Subgroup analysis according to pathological stage revealed that patients in the RELARC-D2 group with pN0 stage achieved a significantly superior 3-year OS rate than did those in the D2 control group (100% vs. 88.9%, P=0.008). We identified no statistically significant differences in survival rates between the remaining subgroups (all P>0.05). Conclusions:A high-quality surgical clinical trial with close follow-up can achieve perioperative safety and a trend toward improved survival outcomes.