Clinical outcomes of TS-1 chemotherapy for advanced and recurrent gastric cancer

Purpose: Titanium silicate (TS)-1 chemotherapy has been widely used against gastric cancer in Japan. The aim of the present study was to assess the efficacy and hematological safety of TS-1 as treatment for advanced and recurrent gastric cancer. Methods: From September 2006 to February 2011, 51 advanced or recurrent gastric cancers were treated with TS-1. One course of treatment consisted of 40, 50, or 60 mg/m2 of TS-1 twice a day for 28 days, followed by withdrawal for two weeks. The primary end point was progression-free survival (PFS), and the secondary end point was overall survival (OS). Results: The disease control rate was 39.2% (complete response, 0/51; partial response, 6/51; stable disease, 14/51; progressive disease, 23/51; not evaluable, 8/51). The median PFS was 4.0 months (95% confidence interval [CI], 2.2 to 5.7); the median PFS of the advanced group was 6.0 months (95% CI, 2.8 to 9.1), and the median PFS of the recurrent group was 3.0 months (95% CI, 1.8 to 4.1). The median OS was 11.0 months (95% CI, 6.3 to 15.6); the median OS of the advanced group was 10.0 months (95% CI, 4.9 to 15.0), and the median OS of the recurrent group was 14.0 months (95% CI, 4.1 to 23.8). Grade 3 or 4 hematological toxicity occurred in three patients (5.9%), anemia occurred in two patients (3.9%), and thrombocytopenia occurred in one patient (2%). Conclusion: TS-1 chemotherapy was safe and effective, with relatively long PFS and OS in patients with advanced and recurrent gastric cancers.