Adjuvant Chemotherapy is an Additional Option for Locally Advanced Gastric Cancer After Radical Gastrectomy with D2 Lymphadenectomy: A Retrospective Control Study

BACKGROUND This study compared the long-term efficacy of different durations of adjuvant chemotherapy for patients with gastric cancer after radical gastrectomy with D2 lymphadenectomy. METHODS We retrospectively identified 428 patients with stage II-III gastric cancer who underwent D2 gastrectomy between 2009 and 2016. Patients were divided into four groups according to the duration of adjuvant chemotherapy, including 0 week (no adjuvant, group A), 20 to 24 weeks (completed 7-8 cycles every 3 weeks or 10-12 cycles every 2 weeks, group B), and 12 to18 weeks (completed 4-6 cycles every 3 weeks or 6-9 cycles every 2 weeks, group C), and less than 12 weeks (received up to 3 cycles every 3 weeks or 5 cycles every 2 weeks, group D). The chemotherapy regimens included XELOX, SOX, and FOLFOX. 5-year overall survival (OS) and disease-free survival (DFS) were analyzed. RESULTS The 5-year OS rates for groups A, B, C, and D were 52.3, 73.7, 72.0, and 53.3%, respectively, and the 5-year DFS rates were 50.0, 68.0, 65.4, and 50.0%, respectively. OS and DFS were higher in group B than in groups A and D. Similarly, patients in group C were more likely to have higher OS and DFS than those in groups A and D. Meanwhile, there were no significant differences in OS and DFS between groups B and C. The multivariate analysis confirmed with high statistical significance the efficacy of complete courses of adjuvant chemotherapy, and, among them, the similar impact of 4-6/6-9 and 7-8/10-12 cycles, resulting in similar HRs vs Group A (0.52 and 0.42, respectively). CONCLUSIONS To reduce toxicity and maintain efficacy, XELOX or SOX chemotherapy regimens administered for 4-6 cycles every 3 weeks or FOLFOX regimen for 6-9 cycles every 2 weeks might be a favorable option for patients with stage II-III gastric cancer after D2 gastrectomy. Prospective multicenter clinical trials with adequate sample sizes are necessary to verify these findings.