Objective:To investigate clinicopathological characteristics and efficacy of conversion therapy in patients with metastatic gastric cancer.Methods:The clinicopathological and follow-up data of metastatic gastric cancer patients at the Department of Gastrointestinal Surgery of Peking University People's Hospital from Jan 2018 to Jun 2021 were retrospectively studied. Multivariate Logistic regression analysis was used to identify independent characteristics for pathological complete response (PCR). The influence of stage of metastatic gastric cancer and pathological response on prognosis were analyzed by Kaplan-Meier curve.Results:A total of 31 patients were enrolled, and 13 tumors located at the cardia or fundus, 8 at body, other 10 at pylorus or antrum . Baseline CT evaluation showed retroperitoneal lymph node metastasis in 10 cases, intraperitoneal metastasis in 10 cases, liver metastasis in 2 cases, adrenal and splenic metastasis in 1 case respectively, and multiple metastasis in 5 cases. After conversion therapy, 8 (26%) cases had pathological T0, 16 cases (52%) had pathological N0 and 7 cases (22%) had pathological complete response. Multivariate Logistic regression analysis showed retroperitoneal lymph node metastasis ( OR: 20.082, 95% CI: 2.141-188.315, P=0.009) was the only independent risk factor of PCR. Meanwhile, Kaplan-Meier curve showed pT0 improved disease-free survival significantly ( P=0.021). Conclusions:Metastatic gastric cancer patients with retroperitoneal lymph node metastasis alone had a tolerable conversion therapy effect. pT0 is a significant factor in improving prognosis.

Objective:To analyze the progress and promotion effect of the national multidisciplinary team(MDT) pilot project of digestive system tumor diagnosis and treatment, for the reference in promoting the popularition of tumor MDT model.Methods:The data of MDT project evaluation forms of 231 digestive system tumor MDT pilot hospitals in 2018(July 2017 to June 2018), 2019(July 2018 to June 2019)and 2020(July 2018 to June 2019)were obtained. The MDT of digestive system tumors, the development of outpatient and inpatient MDT, the distribution of cases, and the management, charging and regional radiation of MDT in the pilot hospital were analyzed. Descriptive analysis and frequency analysis were used for all the data.Results:With pilot hospitals of missing data excluded, the number of pilot hospitals included in the analysis from 2018 to 2020 was 227, 224 and 224, respectively.The number of pilot hospitals carrying out digestive system tumor MDT increased from 174 in 2018 to 222 in 2020, the number of outpatient and inpatient MDT cases increased from 48 332 and 61 823 to 72 493 and 106 899 respectively, and the proportion of pilot hospitals implementing the MDT management system increased from 159 to 214. In 2020, the average expenses of outpatient and inpatient MDT were mainly 200-500 yuan, and 135(60.3%) pilot hospitals became the leading MDT hospitals in the region.Conclusions:The MDT pilot project of digestive system tumors in China has achieved remarkable results.For example, the number of pilot hospitals carrying out MDT keeps increasing year by year, and the pilot hospitals have played a leading role in the region. In order to accelerate the coverage of the tumor MDT model, the authors suggested that the hospitals should optimize MDT in terms of patient accessibility, optimize management mode, promote the medical insurance reimbursement, and strengthen regional influence.

Objective:To investigate the clinicopathological characteristics and prognostic factors of Siewert Ⅱ and Ⅲ adenocarcinoma of esophagogastric junction (AEG).Methods:The retrospetcive cohort study was conducted. The clinicopathological data of 399 patients with AEG who were admitted to Peking University People′s Hospital from January 1998 to December 2015 were collected. There were 318 males and 81 females, aged 66(range, 19-87)years. Observation indicators: (1) clinicopathological characteristics of Siewert Ⅱ and Ⅲ AEG; (2) follow-up and survival; (3) prognostic factors analysis. Patients were followed up by telephone interview and outpatient examination to detect postoperative survival up to December 2018. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range), 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. Kaplan-Meier method was used to draw survival curves and calculate survival rates. Log-rank test was used for survival analysis. Univariate and multivariate analyses were done using the COX proportional hazard model. Results:(1) Clinicopathological characteristics of Siewert Ⅱ and Ⅲ AEG. Of 399 patients, 198 cases were Siewert Ⅱ AEG and 201 cases were Siewert Ⅲ AEG. There were 130 cases undergoing transthoracic radical AEG surgery, 172 cases undergoing trans-abdominal proximal gastrectomy and 97 cases undergoing transabdominal total gastrectomy. The age, tumor diameter, cases with surgical method as transthoracic radical AEG surgery, transabdo-minal proximal gastrectomy and transabdominal total gastrectomy, the number of positive lymph nodes, cases in tumor TNM stage Ⅰ, Ⅱ, Ⅲ, Ⅳ were (65±10)years, (5.1±2.4)cm, 102, 68, 28, 17(range, 12?22), 20, 57, 117, 4 for patients with Siewert Ⅱ AEG, versus (62±12)years, (6.3±3.2)cm, 28, 104, 69,18(range, 14?27), 16, 41, 134, 10 for patients with Siewert Ⅲ AEG, showing significant differ-ences betweeen them ( t=2.83, ?3.82, χ2=66.97, U=17 407.05, 17 532.00, P<0.05). (2) Follow-up and survival. All 399 patients were followed up for 34(range, 2?160)months. The 5-year overall survival rate was 29.3% for patients with Siewert Ⅱ AEG, versus 37.0% for patients with Siewert Ⅲ AEG, showing no significant difference betweeen them ( χ2=1.46, P>0.05). The median survival time and 5-year overall survival rate were 29.0 months [95% confidence interval ( CI) as 23.4?34.6 months] and 22.9% for patients undergoing transthoracic radical AEG surgery, 43.0 months(95% CI as 33.9?52.1 months) and 34.7% for patients undergoing transabdominal proximal gastrectomy, 54.0 months (95% CI as 37.6?70.4 months)and 44.3% for patients undergoing transabdominal total gastrectomy, showing a significant difference in the survival among the 3 groups ( χ2=13.81, P<0.05). Of the 198 Siewert Ⅱ AEG patients, the 5-year overall survival rate was 24.6% for the 96 patients undergoing transabdominal surgery, versus 35.4% for the 102 patients undergoing transthoracic surgery, showing no significant difference in the survival between them ( χ2=3.10, P>0.05). Of the 201 Siewert Ⅲ AEG patients, the 5-year overall survival rate was 40.0% for the 173 patients undergoing transabdominal surgery, versus 16.1% for the 28 patients undergoing transthoracic surgery, showing a significant difference between them ( χ2=11.32, P<0.05). (3) Prognostic factors analysis. Results of univariate analysis showed that surgical method, pathological N staging, patholgical M staging were related factors for prognosis of Siewert Ⅱ and Ⅲ AEG ( hazard ratio=0.68, 1.25, 2.18, 95% CI as 0.54?0.86, 1.15?1.36, 1.28?3.73, P<0.05). Results of multivariate analysis showed that transthoracic approach, pathological stage N2?N3 and pathological stage M1 were independent risk factors for prognosis of Siewert Ⅱ and Ⅲ AEG ( hazard ratio=0.64, 1.25, 2.18, 95% CI as 0.51?0.80, 1.16?1.35, 1.28?3.70, P<0.05). Conclusions:Compared with Siewert Ⅲ AEG, Siewert Ⅱ AEG has a smaller tumor diameter, less positive lymph nodes, poorer prognosis. Transthoracic approach is preffered for the Siewert Ⅱ AEG. Transthoracic approach, pathological stage N2?N3 and pathological stage M1 are independent risk factors for prognosis of Siewert Ⅱ and Ⅲ AEG.

Objective:To investigate the short term efficacy of laparoscopic assisted transanal total mesorectal excision (taTME) for low rectal cancer.Methods:The prospective study was conducted. The clinicopathological data of 80 patients who underwent laparoscopic assisted taTME for low rectal cancer in 8 medical centers，including 27 cases in the First Affiliated Hospital of Jilin University，16 cases in the Daping Hospital of Army Medical University，15 cases in the Beijing Friendship Hospital of Capital Medical University，10 cases in the Peking University Cancer Hospital，7 cases in the Peking Union Medical College Hospital of Chinese Academy of Medical Sciences，2 cases in the Peking University People′s Hospital，2 cases in the Liaoning Cancer Hospital Institute，1 case in the Ruijin Hospital of Shanghai Jiaotong University School of Medicine，from August 2017 to September 2018 were collected. Observation indicators：(1) clinical data of enrolled patients；(2) surgical situations；(3) postoperative histopathological examination；(4)postoperative complications and hospitalization. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers and (or) percentages. Results:(1) Clinical data of enrolled patients：a total of 80 patients were selected for eligibility. There were 59 males and 21 females，aged from 53 to 79 years，with a median age of 61 years. (2）Surgical situations：all 80 patients underwent surgery successfully，including 73 cases undergoing low anterior resection，4 cases undergoing Hartmann operation，1 case undergoing intersphincteric and abdominoperineal resection，1 case undergoing other operations and 1 case missing operation information. Nineteen of the 80 patients underwent transabdominal and transanal operations simultaneously. The operation time of 80 patients was 255 minutes (range，211?305 minutes). Of 80 patients，77 cases had the volume of intraoperative blood loss ≤500 mL，3 cases had the volume of intraoperative blood loss >500 mL，44 cases underwent instrumental anastomosis，24 cases underwent manual anastomosis，12 cases were missing anastomosis information，66 cases had specimens been taken out through anus，2 cases had specimens been taken out through Pfannens-tiel incision，10 cases had specimens been taken out through other ways，2 cases were missing the information of specimens removal ways，57 cases underwent preventive stoma，32 cases under-went anal canal indwelling，30 cases underwent free of splenic flexure and 2 cases were converted to open surgery. (3) Postoperative histopathological examination：of 80 patients，68 cases had the integrity of mesorectal specimens with complete，5 cases had the integrity of mesorectal specimens with near complete，1 case had the integrity of mesorectal specimens with not complete，6 cases were missing the information of integrity of mesorectal specimens，1 case had rectal perforation，1 case had positive circumferential margin and 1 case had positive distal margin. The number of lymph node dissected and diameter of tumor were 12(range，9?16) and 3.0 cm(range，1.9?4.0 cm) of 80 patients. Four of 80 patients achieved pathological complete remission. Cases with tumor stage as T0 stage，Tis stage，T1 stage，T2 stage，T3 stage or T4 stage of the pT staging，cases with tumor stage as N0 stage，N1 stage or N2 stage of the pN staging，cases with tumor stage as M0 stage or M1 stage of the pM staging were 4，2，11，24，35，4，55，21，4，75，5 of 80 patients. (4) Postopera-tive complications and hospitalization：8 of 80 patients underwent anastomotic leakage，including 2 cases with grade A anastomotic leakage，4 cases with grade B anastomotic leakage and 2 cases with grade C anastomotic leakage.Seven of 80 patients underwent intestinal obstruction. The 2 cases with grade A anastomotic leakage were improved after symptomatic drug treatment，the 4 cases with grade B anastomotic leakage were improved after treatment with antibiotics or catheter drainage and the 2 cases with grade C anastomotic leakage were improved after operation. The duration of hospital stay of 80 patients was 14 days(range，11?21 days). No patient died during hospitalization.Conclusion:Laparoscopic assisted taTME for low rectal cancer is safe and feasible，which has a good short term efficacy.

Objective:To investigate the incidence and influencing factors of anastomotic leakage after anterior resection (AR) for rectal cancer.Methods:The retrospective case-control study was conducted. The clinicopathological data of 1 243 patients with rectal cancer who were admitted to 3 medical centers between August 2008 and July 2017 were collected, including 512 in the Beijing Friendship Hospital of Capital Medical University, 480 in the Cancer Hospital of Chinese Academy of Medical Sciences, 251 in the Peking University People′s Hospital. There were 734 males and 509 females, aged from 25 to 89 years, with an average age of 65 years. All patients underwent AR for rectal cancer. Observation indicators: (1) surgical situations and incidence of postoperative anastomotic leakage; (2) influencing factors for postoperative anastomotic leakage. Measurement data with skewed distribution were represented as M (range). Count data were represented as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Univariate analysis was conducted using the chi-square test. Multivariate analysis was conducted using the Logistic regression model based on factors with P<0.10 in the univariate analysis. Results:(1) Surgical situations and incidence of postoperative anastomotic leakage: all the 1 243 patients with rectal cancer underwent successfully AR including 219 undergoing defunctioning stoma and 1 024 undergoing non-defunctioning stoma, of which 70 patients had postoperative anastomotic leakage, with a total incidence rate of 5.632%(70/1 243). The incidence rates of grade A anastomotic leakage, grade B anastomotic leakage, and grade C anastomotic leakage were 27.1%(19/70), 21.4%(15/70), 51.4%(36/70), respectively. (2) Influencing factors for postoperative anastomotic leakage: results of univariate analysis showed that gender, surgical procedure, volume of intra-operative blood loss, and pathological metastasis staging were related factors for anastomotic leakage after AR ( χ2=8.518, 6.548, 10.834, 4.501, P<0.05). Results of multivariate analysis based on factors with P<0.10 in the univariate analysis showed that male and volume of intraoperative blood loss≥100 mL were independent risk factors for anastomotic leakage after AR [ odds ratio ( OR)=2.250, 1.949, 95% confidence interval ( CI): 1.281-3.952, 1.142-3.324, P<0.05)]; defunctioning stoma was an independent protective factor for anastomotic leakage after AR ( OR=0.449, 95% CI: 0.201-1.001, P<0.05). Subgroup analysis on effects of defunctioning stoma versus non-defunctioning stoma on grade of anastomotic leakage showed that percentage of grade C anastomotic leakage for defunctioning stoma group was 14.3%(1/7), versus 55.6%(35/63) for non-defunctioning stoma group, with a significant difference between the two groups ( χ2=9.570, P<0.05). Conclusions:Male and volume of intraoperative blood loss≥100 mL are independent risk factors for anastomotic leakage after AR. Defunctioning stoma is an independent protective factor for anastomotic leakage after AR. For male patients and patients with large volume of intraoperative blood loss, defunctioning stoma is recommended to reduce the incidence of postoperative anastomotic leakage.

Objective:To investigate the role of indocyanine green(ICG) fluorescence imaging in laparoscopic anterior resection for rectal cancer.Methods:A retrospective analysis was performed on 7 patients who had undergone laparoscopic anterior resection with the use of ICG fluorescence imaging at Peking University People′s Hospital between Oct 2018 and Mar 2019. The clinicopathological variables, surgical factors, short-term outcome and complications were analyzed.Results:The median operation time was 185 min. The median estimated blood loss was 50 ml. The median time from ICG injection to anastomotic perfusion was 45 s. One patient received extended proximal resection of bowel due to poor perfusion as suggested by ICG imaging. The median time to soft diet was 4 days, and the median hospital stay was 8 days. The median number of lymph nodes harvested was 16. There were no major complications in all these patients. No adverse events related to ICG were recorded.Conclusions:ICG fluorescence imaging was safe and effective in detecting insufficient blood supply around newly established bowel anastomsis, hence potentially reducing the anastomotic leakage rate.

With certain advantages of superior surgical fields and better chances for anus reservation, transanal total mesorectal excision (TaTME) is a novel surgical approach for low rectal cancer. Guidelines recommend multidisciplinary team (MDT) work as a clinical routine for standardized treatment of rectal cancer. Indication of TaTME depends on multidisciplinary discussion including preoperative staging, prediction of recurrence risks. Standardized preoperative evaluation by MDT and decisions after MDT discussion are the guarantee for the stan-dardized implementation and reasonable promotion of TaTME. Meanwhile, as a procedure for improving local efficacy of rectal cancer, TaTME could save a part of patients with low rectal cancer the trouble of neoadjuvant chemoradiotherapy based on accurate staging by radiologists. That might upgrade status of colorectal surgeons in the MDT and contribute to optimize both curative effects and health economics.

Objective:To investigate the efficacy and prognosis of three surgical methods for presacral recurrent rectal cancer (PRRC).Methods:A retrospective cohort study was carried out. Case inclusion criteria: (1) primary rectal cancer without distant metastasis and undergoing radical surgery; (2) patients undergoing radical surgery after the diagnosis of PRRC; (3) complete inpatient, outpatient and follow-up data. Clinical data of 47 patients meeting the above criteria who underwent operation at the Department of Gastrointestinal Surgery, The Peking University People's Hospital from January 2008 to December 2017 were reviewed and analyzed retrospectively. Of the 47 patients, 31 were male and 16 were female; the mean age was 57 years old; 9 (19.1%) were low differentiation or signet ring cell carcinoma, 38 (80.9%) were medium differentiation; 19 (40.4%) received neoadjuvant therapy. According to operative procedure, 22 patients were in the abdominal/abdominoperineal resection group, 15 in the sacrectomy group and 10 in the abdominosacral resection group. The operative data, postoperative data and prognosis were compared among the three groups. Survival curve was conducted using the Kaplan-Meier method, and log-rank test was used to compare survival difference among three groups.Results:There were no significant differences in baseline data among three groups (all P>0.05). All the 47 patients completed the radical resection successfully. The mean operation time was (4.7±2.1) hours, the median intraoperative blood loss was 600 ml, and the median postoperative hospitalization time was 17 days. Fifteen cases (31.9%) had perioperative complications, of which 3 cases were grade III-IV. There was no perioperative death. The mean operative time was (7.4±1.6) hours in the abdominosacral resection group, (4.9±1.6) hours in the abdominal/abdominoperineal resection group, and (3.0±1.1) hours in the sacroectomy group, with a significant difference ( F=25.071, P<0.001). There were no significant differences in intraoperative blood loss, postoperative hospitalization days and perioperative complications among the three groups (all P>0.05). The median follow-up period of all the patients was 24 months, 12 cases (25.5%) developed postoperative dysfunction. The incidence of postoperative dysfunction in the abdominosacral resection group was 5/10, which was higher than 4/15 in the sacrectomy group and 3/22 (13.6%) in the abdominoperineal resection group with statistically significant difference (χ 2=9.307, P=0.010). The 1-year and 3-year overall survival rates were 86.1% and 40.2% respectively. The 1-year overall survival rates were 86.0%, 86.7% and 83.3%, and the 3-year overall survival rates were 33.2%, 40.0% and 62.5% in the abdominal/abdominoperineal resection group, sacrectomy group and abdominosacral resection group, respectively, whose difference was not statistically significant (χ 2=0.222, P=0.895). Conclusions:Abdominal/abdominoperineal resection, sacrectomy and abdominosacral resection are all effective for PRRC. Intraoperative function protection should be concerned for patients undergoing abdominosacral resection.

Objective:To investigate the clinicopathological features and prognostic factors in patients with presacral recurrent rectal cancer (PRRC).Methods:PRRC was defined as recurrence of rectal cancer after radical surgery involving posteriorly the presacral soft tissue, the sacrum/coccyx, and/or sacral nerve root. The diagnosis is confirmed with clinical symptoms (pain of pelvis/back/lower limb, bloody stools, increased frequency of defecation, and abnormal secretions), physical examination of perineal or pelvic masses, radiological findings, colonoscopy with histopathological biopsy, and the evaluation by multi-disciplinary team (MDT). Inclusion criteria: (1) primary rectal cancer undergoing radical surgery without distant metastasis; (2) PRRC was diagnosed; (3) complete inpatient, outpatient and follow-up data. According to the above criteria, clinical data of 72 patients with PRRC in Peking University People′s Hospital from January 2008 to December 2017 were retrospectively analyzed. The clinicopathological features and follow-up data were summarized. Cox proportional hazard models was used to analyze the prognostic factors of PRRC.Results:Among 72 patients, 45 were male and 27 were female with a male-to-female ratio of 1.7:1.0. The median age at recurrence was 58 (34 to 83) years and the median interval from surgery to recurrence was 2.0 (0.2 to 17.0) years. The main symptom was pain in 48.6% (35/72) of patients. In addition, gastrointestinal symptoms were found in 25.0% (18/72) of patients. The presacral recurrent sites were presacral fascia in 36 (50.0%) patients, lower sacrum (S3~S5 or coccyx) in 25 (34.7%) patients, and higher sacrum (S1~S2) in 11 (15.3%) patients. Forty-seven (65.3%) patients underwent radical surgery (abdominal resection, abdominoperineal resection, sacrectomy, abdominosacral resection), 12 (16.7%) underwent non-radical surgery (colostomy, cytoreductive surgery), and 13 (18.1%) did not undergo any surgery but only receive palliative chemoradiotherapy and nutritional support treatment. Thirty-three (45.8%) patients received radiotherapy and/or chemotherapy (oxaliplatin, 5-fluorouracil, capecitabine, irinotecan, etc.). All the patients received follow-up, and the median follow-up time was 19 (2 to 72) months. The median overall survival time was 14 (1 to 65) months. The 1- and 3-year overall survival rates were 67.1% and 32.0%, respectively. Univariate analysis showed that age at recurrence ( P=0.031) and radical resection ( P<0.001) were associated with prognosis. Multivariate analysis demonstrated that radical resection was independent factor of good prognosis (RR=0.140, 95%CI: 0.061-0.322, P<0.001). Conclusions:Patients tend to develop presacral recurrent rectal cancer within 2 years after primary surgery. The main symptom is pain. Patients undergoing radical resection have a relatively good prognosis.

Radical resection is one of the most important treatment for rectal cancer, which requires not only removal of adequate bowel and mesorectum around the tumor, but also thorough lymphadenectomy. Besides, postoperative complications are surgeons′ concerns as well. According to different ways to manage inferior mesenteric artery, procedures could be divided into two groups: inferior mesenteric artery (IMA) high ligation and low ligation, which lead to various outcomes of the extent of lymph nodes dissection, survival, preservation of intestinal blood supply, incidence of anastomotic leakage, and postoperative functions including defecation function, urinary function and sexual function. Author believes that for those patients with clinical stage T1, low ligation and D2 lymph nodes dissection could be considered. However, for patients with locally advanced carcinomas (clinical stage T2+or N+), especially suspicious metastasis of lymph nodes around IMA root, high ligation and D3 lymph node dissection is suggested to ensure en bloc resection. As for those patients with high risks for compromised intestinal blood supply, preservation of left colic artery plus D3 lymph nodes dissection might be a feasible way. Intraoperative indocyanine green fluorescent imaging might play a role in quality control of lymphadenectomy.