[Safety and effectiveness of oxaliplatin combined with capecitabine or oxaliplatin combined with S-1 neoadjuvant chemotherapy in the treatment of advanced gastric cancer].

To explore the safety and efficacy of oxaliplatin plus capecitabine (CapeOX) or oxaliplatin plus S-1 (SOX) regimen neoadjuvant chemotherapy in the treatment of advanced gastric cancer. A retrospective cohort study was performed. Clinical data of patients diagnosed as advanced gastric cancer undergoing CapeOX/SOX neoadjuvant chemotherapy and standard laparoscopic radical operation for gastric cancer in Ruijin Hospital of Shanghai Jiaotong University School of Medicine from April 2016 to April 2019 were retrospectively collected. Inclusion criteria were as follows: (1) age≥18 years; (2) gastric adenocarcinoma was confirmed by histopathology and the clinical stage was T3-4aN+M0; (3) tumor could be resectable; (4) preoperative neoadjuvant chemotherapy was CapeOX or SOX regimen without radiotherapy or other regimen chemotherapy; (5) no other concurrent malignant tumor; (6) the Eastern Cooperative Oncology Group (ECOG) score ≤ 1; (7) no bone marrow suppression; (8) normal liver and kidney function. Exclusion criteria were as follows: (1) patients with recurrent gastric cancer; (2) patients receiving emergency surgery due to tumor perforation, bleeding, obstruction, etc.; (3) allergy to oxaliplatin, S-1, capecitabine or any drug excipients; (4) diagnosed with coronary heart disease, cardiomyopathy, or the New York Heart Association class III or IV; (5) pregnant or lactating women. A total of 118 patients were enrolled as the neoadjuvant chemotherapy group, and 379 patients with locally advanced gastric cancer who received surgery combined with postoperative adjuvant chemotherapy over the same period simultaneously were included as the adjuvant chemotherapy group. After propensity score matching was performed including gender, age, ECOG score, tumor site, clinical stage, chemotherapy regimen and other factors by 1:1 ratio, there were 40 cases in each group. The differences between the two groups in general conditions, efficacy of neoadjuvant chemotherapy, intraoperative conditions, postoperative conditions, histopathological results, chemotherapy-related adverse events, and survival status were compared and analyzed. Comparison of baseline demographics between the two groups showed no statistically significant difference (all >0.05). In the neoadjuvant chemotherapy group, 5.0% (2/40) of patients achieved clinical complete response, 57.5% (23/40) achieved partial response, 32.5% (13/40) remained stable disease, and 5.0% (2/40) had disease progression before surgery. Objective response rate was 62.5% (25/40), and disease control rate was 95.0% (38/40). There were no statistically significant differences between neoadjuvant chemotherapy group and adjuvant chemotherapy group in terms of operation time, intraoperative blood loss, number of lymph node harvested, length of postoperative hospital stay, and postoperative mortality and morbidity (all >0.05). Postoperative complications were well managed with conservative treatment. No Clavien-Dindo IV or V complications were observed in both groups. Pathological results showed that the proportion of patients with pathological stage T1 in the neoadjuvant chemotherapy group was significantly higher than that in the adjuvant chemotherapy group [27.5% (11/40) vs. 5.0% (2/40)], while the proportion of patients with pathological stage T3 was significantly lower than that in the adjuvant chemotherapy group [20.0% (8/40) vs. 45.0% (18/40)], with statistically significant difference (χ(2)=15.432, =0.001). In the neoadjuvant chemotherapy group, there were 4 cases of tumor regression grade 0, 8 cases of grade 1, 16 cases of grade 2, and 12 cases of grade 3. The pathological complete response rate was 10% (4/40), the overall pathological response rate was 70.0% (28/40). There was no statistically significant difference in the incidence of chemotherapy-related adverse events between neoadjuvant chemotherapy group and adjuvant chemotherapy group [40% (16/40) vs. 37.5% (15/40), 0.05). There were no statistically significant differences in OS (43 months vs. 40 months) and 3-year OS rate (66.1% vs. 59.8%) between neoadjuvant chemotherapy group and adjuvant chemotherapy group (=0.428). The disease-free survival (DFS) and 3-year DFS rates of the neoadjuvant chemotherapy group were significantly superior to those of the adjuvant chemotherapy group (36 months vs. 28 months, 51.4% vs. 35.8%, =0.048). CapeOX or SOX regimen neoadjuvant chemotherapy is a safe, effective and feasible treatment mode for advanced gastric cancer without increasing surgical risk and can improve the DFS of patients.