Comparison of safety and efficacy of S-1 monotherapy and S-1 plus cisplatin therapy in elderly patients with advanced gastric cancer

Although S-1 plus cisplatin (SP) therapy is recognized as the standard treatment for advanced gastric cancer (AGC) in Japan, its safety and efficacy in elderly patients have not been investigated sufficiently. We retrospectively reviewed the data of 58 patients with AGC selected from 82 consecutive patients who were a parts per thousand yen70 years old and were treated with SP or S-1 monotherapy as the first-line therapy. In SP, S-1 (40 mg/m(2), bid) was administered for 3 weeks and cisplatin (60 mg/m(2)) on day 8, every 5 weeks. In S-1 monotherapy, S-1 (40 mg/m(2), bid) was administered for 4 weeks, every 6 weeks. SP and S-1 was administered in 21 and 37 patients, respectively. There were some differences in patient characteristics between the treatment groups, such as histological type (P = 0.16); the presence of liver metastasis (P = 0.07); and the presence of peritoneal metastasis (P = 0.02). The incidences of grade 3/4 hematological toxicities were 57% (12/21) in the SP and 35% (13/37) in the S-1 group (P = 0.17). Those of non-hematological toxicities were 14% (3/21) and 14% (5/37) for anorexia, 10% (2/21) and 14% (5/37) for fatigue, and 5% (1/21) and 5% (2/37) for nausea in the SP and S-1 groups, respectively. Median progression-free survival and median overall survival in the SP and S-1 groups were 5.0 and 5.2 months, and 14.4 and 10.9 months, respectively. SP and S-1 therapy were both feasible in elderly patients, though there is the risk of a high incidence of hematological toxicities.