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.