Chemotherapy for gastric cancer that recurs after adjuvant chemotherapy with S-1.

We retrospectively analyzed the efficacy of chemotherapy in patients whose gastric cancer recurred after adjuvant chemotherapy with S-1. A total of 51 patients were evaluated. Twenty-one patients received S-1-containing chemotherapy as first-line treatment after recurrence [cohort A: S-1 plus cisplatin (n = 10), S-1 monotherapy (n = 7), S-1 plus irinotecan (n = 3) and S-1 plus docetaxel (n = 1)]. The other 30 patients received a non-S-1-containing regimen [cohort B: paclitaxel or docetaxel (n = 22), irinotecan plus cisplatin (n = 6) and other drugs (n = 2)]. No objective responses occurred in cohort A, while five patients achieved a partial response in cohort B (response rate, 0 versus 16%; P = 0.04). Median progression-free survival was significantly longer in cohort B than in cohort A (4.3 versus 2.3 months, P = 0.02). S-1-containing chemotherapy does not appear to be effective in patients whose gastric cancer recurs after adjuvant S-1 chemotherapy. Other chemotherapeutic agents should be evaluated in this setting.