Objective:To investigate the influence of neoadjuvant chemotherapy on safety and prognosis of patients undergoing multivisceral resection for gastric cancer.Methods:The pro-pensity score matching (PSM) and retrospective cohort study was conducted. The clinicopathological data of 144 patients with gastric cancer who underwent multivisceral resection in the Fudan University Shanghai Cancer Center from December 2011 to December 2020 were collected. There were 95 males and 49 females, aged (56±13)years. Of 144 patients, 27 cases undergoing neoadjuvant chemotherapy and postoperative adjuvant chemotherapy were divided into the neoadjuvant chemotherapy group, and 117 cases undergoing postoperative adjuvant chemotherapy were divided into the adjuvant chemotherapy group. Observation indicators: (1) PSM and comparison of general data of patients between the two groups after matching; (2) surgical and postoperative conditions; (3) prognosis. PSM was done by the 1∶1 nearest neighbor matching method, with the caliper setting as 0.02. Measurement data with normal distribution were expressed as Mean± SD. Measurement data with skewed distribution were expressed as M(range), and comparison between groups was conducted using the rank sum test. Count data were expressed as absolute numbers, comparison between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the non-parameter test. The Kaplan-Meier method was used to draw survival curves and calculate survival rate, and the Log-Rank test was used for survival analysis. Results:(1) PSM and comparison of general data of patients between the two groups after matching. Of 144 patients, 46 cases were successfully matched, including 23 cases in the neoadjuvant chemotherapy group and 23 cases in the adjuvant chemotherapy group, respectively. The elimination of preoperative hemoglobin, clinical TNM staging confounding bias ensured comparability between the two groups after PSM. (2) Surgical and postoperative conditions. Of 46 patients, 26 cases underwent gastrectomy with one organ resection, 16 cases underwent gastrectomy with two organs resection, and 4 cases underwent gastrectomy with three organs resection. Of the patients with multivisceral resection, the proportion of patients undergoing combined splenectomy, pancreatectomy, colon resection, liver resection, and small intes-tinal resection was 69.6%(32/46), 39.1%(18/46), 32.6%(15/46), 8.7%(4/46), 2.2%(1/46), respectively. Cases with D 1 lymph node dissection, cases with D 2 lymph node dissection, cases with R 0 resection, cases with R 1 resection in the neoadjuvant chemotherapy group and the adjuvant chemotherapy group were 1, 22, 23, 0 and 0, 23, 23, 0, respectively, showing no significant difference in the above indicators between the two groups ( P>0.05). The number of lymph node dissected, the volume of intraoperative blood loss, duration of postoperative hospital stay in the neoadjuvant chemotherapy group and the adjuvant chemotherapy group were 28(range, 22-37), 150 (range, 100-200)mL, 11(range, 8-16)days and 25(range, 18-32), 150(range, 100-200)mL, 11(range, 9-18)days, respec-tively, showing no significant difference in the above indicators between the two groups ( Z=-1.13, -0.32, -0.50, P>0.05). Cases with complications ≥grade Ⅱ of Clavien-Dindo classification during the postoperative 30 days were 2 in the neoadjuvant chemotherapy group, including 1 case of abdominal abscess and 1 case of pneumonia. Cases with complications ≥grade Ⅱ of Clavien-Dindo classification during the postoperative 30 days were 8 in the adjuvant chemotherapy group, including 3 cases of abdominal abscess, 2 cases of anastomotic fistula, 1 case of pneumonia, 1 case of pancreatic fistula, 1 case of gastric emptying disability. There were significant differences in the complications ≥grade Ⅱ of Clavien-Dindo classification between the neoadjuvant chemotherapy group and the adjuvant chemotherapy group ( χ2=4.60, P<0.05). There was no significant difference in the abdominal abscess, anastomotic fistula, pneumonia, pancreatic fistula, gastric emptying disability between the two groups ( P>0.05). None of patient died in either of the neoadjuvant chemotherapy group and the adjuvant chemotherapy group. (3) Prognosis. Of 46 patients, 43 cases were followed up for 15.4(range, 3.0-84.0)months. The overall survival time of patients in the neoadjuvant chemotherapy group and the adjuvant chemotherapy group were (14±10)months and (24±22)months, showing no significant difference between them ( hazard ratio=0.82, 95% confidence interval as 0.28-2.40, P>0.05). Conclusion:Compared with postoperative adjuvant chemotherapy, neoadjuvant chemotherapy does not increase the surgical risk of locally advanced gastric cancer patients undergoing multivisceral and radical resection, and can reduce the incidence of complications ≥grade Ⅱ of Clavien-Dindo classification during the postoperative 30 days, but does not improve patient survival.

Objective: To investigate the differences of clinicopathological features, diagnosis, treatment and prognosis between patients with extra-gastrointestinal stromal tumors (EGIST) and duodenal gastrointestinal stromal tumors (DGIST). Methods: A retrospective case - control study was performed. Case inclusion criteria: (1) tumor confirmed by histology and pathology; (2) primary tumor locating in the extra - gastrointestinal tract or duodenum; (3) without other synchronous tumors; (4) complete clinical and pathological data. Clinical data of 20 EGIST patients and 32 DGIST patients from March 2011 to September 2016 at Department of Gastrointestinal Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine were retrospectively collected and analyzed. The observational parameters included clinicopathological characteristics, treatment and prognosis conditions. Continuous data of abnormal distribution were expressed as median (range) and compared using the Mann-Whitney U-test. Survival curves were drawn by the Kaplan-Meier method and compared with the Log-rank test. Results: Of the 20 EGIST patients, 8 were males and 12 were females with age of 61.0 (30.0 to 86.0) years and of the 32 DGIST patients, 12 were males and 20 were females with age of 55.5 (27.0 to 70.0) years. Compared with DGIST patients, EGIST patients were older (U=188.000, P=0.012], had larger tumor size [10.0 (3.0 to 29.0) cm vs. 4.0 (1.5 to 10.0) cm, U=98.500, P<0.001] and higher ratio of high risk classification [85.0% (17/20) vs. 12.5% (4/32), χ²=26.870, P<0.001]. Among the 20 EGIST patients, 5 were diagnosed with distal metastasis and received imatinib (400 mg/d), and the other 15 patients underwent radical resection who were included in survival analysis. All the 32 DGIST patients underwent radical resection. The median follow-up of whole group was 43 (14 to 76) months. The 3-year recurrence/metastasis-free survival rate of 15 cases undergoing radical resection in the EGIST group was 85.6%, which was lower than that of the DGIST group (88.6%), and the difference was not statistically significant (P=0.745). There was no significant difference in the 3-year overall survival rate between the EGIST group (92.9%) and the DGIST group (100%) (P=0.271). Conclusions As compared to DGIST, EGIST mostly occurs in those with older age, larger tumor size and higher risk grade. The prognosis of EGIST patients after radical resection is similar to that of DGIST patients.