Association of fluoropyrimidines, platinum agents, taxanes, and irinotecan in any line of chemotherapy with survival in patients with advanced gastric cancer

Although fluoropyrimidines, platinum agents, taxanes, and irinotecan are used in the treatment of advanced gastric cancer (AGC), it remains unclear whether these agents in any line of chemotherapy are associated with overall survival (OS) in these patients. We retrospectively analyzed 704 patients with AGC. To avoid possible lead-time bias, we applied time-varying covariate analysis for chemotherapy with four agents in any line. Median OS was 12.3 months. The frequency of exposure to each agent class during all lines of treatment was 92.6% for FU (5-fluorouracil or oral fluoropyrimidine), 48.2% for platinum agents, 65.1% for taxanes, and 39.1% for irinotecan. According to a multivariate Cox model with exposure to each agent class as a time-varying covariate, the hazard ratios (HRs) of death were 0.41 (95% confidence interval [CI], 0.27-0.57; p < 0.001) for FU, 0.71 (95% CI, 0.58-0.84; p < 0.001) for platinum agents, 0.51 (95% CI, 0.41-0.63; p < 0.001) for taxanes, and 0.53 (95% CI, 0.43-0.65; p < 0.001) for irinotecan. Although other agents were used in 18.6% of the patients, they did not affect survival. Each of the four agent classes (FU, platinum agents, taxanes, and irinotecan) appears to be independently associated with improved OS in patients with AGC regardless of timing. This result suggests the importance of developing strategies which make these active agents available to all patients with AGC to prolong OS.