Phase II study of S-1 monotherapy in patients over 75 years of age with advanced gastric cancer (OGSG0404).

BACKGROUND

S-1+cisplatin (CDDP) is the standard treatment for advanced gastric cancer (AGC) in Japan and Korea. However, the usefulness of S-1 based chemotherapy for elderly patients is unclear. Therefore, we conducted a multicenter phase II study of S-1 monotherapy for AGC in elderly patients.

MATERIALS AND METHODS

Chemotherapy-naïve patients aged over 75 years with AGC were enrolled. The starting dose of S-1 was determined on the basis of body surface area and modified according to the creatinine clearance value. S-1 was administered twice a day during a 4-week period followed by a 2-week rest period.

RESULTS

Thirty-five patients were enrolled. The response rate (RR) was 14.3% and the median overall survival was 14.6 months. Grade 3 or more severe adverse events consisted of anaemia (3%), neutropaenia (3%), anorexia (3%), and fatigue (6%). There were no treatment-related deaths.

CONCLUSION

Our study indicates that S-1 monotherapy is safe and well tolerated in chemotherapy-naïve elderly patients with AGC, but exerts limited activity when given using a tailor-made dosing strategy based on renal function.