Comparison of Safety and Efficacy of S-1 Monotherapy and S-1 Plus Cisplatin Therapy in Elderly Patients with Advanced Gastric Cancer

Background: 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.

Methods: We retrospectively reviewed the data of 58 patients with AGC selected from 82 consecutive patients who were ≥70 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.

Results: 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.

Conclusion: SP and S-1 therapy were both feasible in elderly patients, though there is the risk of a high incidence of hematological toxicities.