Chemotherapy for metastatic disease: review from JCOG trials

The Gastrointestinal Oncology Study Group of Japan Clinical Oncology Group (GIOSG/JCOG) has conducted several clinical trials to establish standard chemotherapy for unresectable or recurrent gastric cancer. From the late 1980s to early 1990s, two phase II studies by JCOG evaluated oral fluoropyrimidines, and others introduced Western chemotherapy regimens. Thereafter, the first phase III study (JCOG9205), comparing 5-fluorouracil (5-FU), 5-FU plus ciplatin (CDDP) (FP), and uracil and tegafur (UFT) plus mitomycin (UFTM), could not show a survival benefit of either FP or UFTM over 5-FU alone. In the late 1990s, new active agents such as irinotecan (CPT-11) and S-1 (new oral fluoropyrimidine) showed promising results in their phase II trials. The latest phase III study (JCOG9912), comparing 5-FU, CPT-11 plus CDDP, and S-1, showed significant noninferiority of S-1 to 5-FU in overall survival, associated with a better response rate and progression-free survival and acceptable toxicities, and concluded that S-1 should be considered for the standard chemotherapy of unresectable or recurrent gastric cancer. Simultaneously, another Japanese phase III trial comparing S-1 with S-1 plus CDDP showed a survival benefit of S-1 plus CDDP. At present, S-1 plus CDDP is recognized as standard chemotherapy for unresectable or recurrent gastric cancer, and new treatment with molecular target agents is under development.