Randomized Controlled Study of Postoperative Adjuvant Therapy for Gastric Cancer Using TS-1 or TS-1+PSK

Inclusion Criteria:

* Patients with microscopic stage II or IIIA resectable gastric cancer
* Patients who have not received preoperative cancer therapy (radiotherapy, chemotherapy or immunotherapy)
* Patients with serum immunosuppressive acidic protein (IAP) measured within 2 weeks before surgery
* Patients with no metachronous or synchronous multiple cancer
* Patients without severe impairment of renal, hepatic and bone marrow functions
* Patients who are judged to be capable of tolerating surgery
* Patients with preoperative performance status 0 to 2
* Patients with no serious concurrent complications (such as bone marrow suppression, diarrhea and infection)
* Patients who are judged to be capable of tolerating this treatment, and who have given written informed consent to participate in this study

Exclusion Criteria:

* Patients with fresh hemorrhage from the gastrointestinal tract
* Patients with retention of body fluid necessitating treatment
* Patients with infection, intestinal palsy or intestinal occlusion
* Patients who are pregnant or hope to become pregnant during the study period
* Patients with diabetes treated by continuous use of insulin or showing poor glycemic control
* Patients with a history of ischemic heart disease
* Patients with concurrent psychiatric disease or psychotic symptoms, and judged to have difficulties participating in the study
* Patients receiving continuous administration of steroids
* Patients who have experienced serious drug allergy in the past
* Others, patients judged by the investigator or subinvestigator to be inappropriate as subject