Patients: clinical Stage III gastric cancer patients. Informed consent will be obtained before surgery. Eligible patients: surgical Stage II, IIIA and IIIB gastric cancer patients. Chemosensitivity test: The surgical specimen will be sent Mitsubishi BCL, Co. Ltd. to be tested by CD-DST chemosensitivity test and RT-PCR for thymidylate synthetase and dihydropyrimidine dehydrogenase mRNA. The test results will be blinded for the doctors on duty.