 The cohorts 1 an d2 will be conducted consecutively, started with cohort 1. Cohort 1 consists of 30 patients who receive S-1 twice daily for 18 cycles D1-14 q 3 wks. Cohort 2 consists of 30 patients who receive S-1 twice daily for 9 cycles D1-28, q 6 wks. Both cohorts will start with 2x 30 mgm2 BSA. Two dose reductions will be allowed per protocol. 