Multicenter phase II study of capecitabine plus oxaliplatin in older patients with advanced gastric cancer: the Tokyo Cooperative Oncology Group (TCOG) GI-1601 study.

Background: Capecitabine plus oxaliplatin (CapeOX) is a standard treatment option for advanced gastric cancer (AGC). We conducted a prospective multicenter phase II study to evaluate the efficacy and safety of CapeOX as a first-line therapy for AGC in older patients.

Methods: Chemotherapy-naive patients aged ≥ 70 years with AGC were eligible. Initial treatment comprised capecitabine (2000 mg/m on days 1-14) and oxaliplatin (130 mg/m on day 1) every 3 weeks. After the initial feasibility assessment, the dose was reduced considering toxicity (capecitabine, 1500 mg/m on days 1-14; and oxaliplatin, 100 mg/m on day 1 every 3 weeks). The primary endpoint was overall survival (OS).

Results: In total, 108 patients were enrolled, of whom 104 were evaluated. Thirty-nine patients received the original-dose treatment, whereas 65 received the reduced-dose treatment. The median OS, progression-free survival (PFS), and time to treatment failure (TTF) were 12.9 (95% CI 11.6-14.8), 5.7 (95% CI 5.0-7.0), and 4.3 (95% CI 3.9-5.7) months, respectively, for all patients; 13.4 (95% CI 9.5-16.0), 5.8 (95% CI 4.1-7.8), and 5.3 (95% CI 3.5-7.2) months in the original-dose group; and 12.8 (95% CI 11.3-15.3), 5.7 (95% CI 4.4-7.0), and 4.1 (95% CI 3.7-5.7) months in the reduced-dose group. The most common grade 3/4 toxicities were neutropenia (17.9%), anemia (12.8%), and thrombocytopenia (12.8%) in the original-dose group and neutropenia (13.8%) and anorexia (12.3%) in the reduced-dose group.

Conclusions: These findings demonstrate CapeOX's efficacy and safety in older AGC patients.