Diverse eastern and Western approaches to the management of gastric cancer.

There are still remarkable disparities in the treatment of gastric cancer between the East and the West. Treatment outcomes for this disease have improved in Japan due to early detection, endoscopic treatment, and increased surgical expertise with D2 resection. Similar improvements have been seen in Korea, whereas gastric cancer remains a virulent disease in Western countries. In the field of adjuvant therapy, baseline surgical quality and outcomes were quite different between studies conducted in Japan and Western countries, and Japanese oncologists have not accepted the Western results. In Japan, more radical surgery than standard D2 dissection failed to demonstrate any superiority in two recent randomized trials, whereas a significant survival benefit of adjuvant chemotherapy using S-1 was obtained in the large, nationwide randomized trial. These results will change Japanese practice guidelines and approaches in designing clinical trials in this field. Several disparities are also evident in the results of chemotherapy trials for advanced gastric cancer. In Western studies, two triplet regimens have already demonstrated significant prolongation of survival; however, these benefits seem to be marginal and the regimens may be replaced by newer treatments. Studies testing newer treatments in 1,300 patients in Japan are anticipated to produce median survival duration of more than 12 months. Several molecular targeting agents are being investigated in international trials based on promising results in preliminary studies, discussion of which is beyond the scope of this paper. Although various disparities between regions must be overcome, it is time to pursue further benefits by incorporating new agents into treatment approaches for patients with gastric cancer.