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 D₁ lymph node dissection, cases with D₂ lymph node dissection, cases with R₀ resection, cases with R₁ 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.