Chemotherapy for advanced gastric cancer: future perspective in Japan.

Differences in clinical outcomes between advanced gastric cancer (AGC) in Asia and that in other regions have been discussed for a long time, although no major significant differences in molecular profiles have been reported. The anti-human epidermal growth factor receptor 2 antibody trastuzumab and the anti-vascular endothelial growth factor receptor 2 monoclonal antibody ramucirumab were both approved as a treatment for AGC on the basis of global phase 3 trials including Japan. In recent years, others new agents for treatment of AGC have been investigated in global or Asian studies. Randomized phase 2 trials in Japan showed a higher response rate to S-1 plus leucovorin and oxaliplatin than to standard S-1 plus cisplatin, which is the rationale for an ongoing phase 3 trial in Asia (SOLAR trial). A recent global phase 1 trial of the anti-programmed cell death 1 monoclonal antibody pembrolizumab showed similar efficacy results in Asian patients and non-Asian patients, which led to large global phase 2 and phase 3 studies. Although the perspective of treatment of AGC in the near future depends on the results of ongoing large clinical trials, individualized choice of treatment based on more detailed molecular information will become important.