Co-operative groups in the development of chemotherapy for gastric cancer

In the multimodality treatment strategy for gastric cancer, chemotherapy has an important role in conferring survival benefit. For the last three decades, great progress has been achieved in adjuvant and palliative chemotherapy. Powerful combination regimens using doublet or triplet cytotoxic agents have been developed and new molecular targeted drugs, including trastuzumab and ramucirumab, have been introduced in clinical practice. These advances have resulted from the accumulation of many clinical trials. A well-designed phase III trial can change standard treatment; however, such a trial is hard to complete due to its huge cost and need to recruit many patients. Some co-operative groups have actively made efforts at fundraising and patient recruitment, which can make implementation of high-quality and large-scale phase III trials possible. This review summarizes the development of chemotherapy for gastric cancer with focus on co-operative groups around the world, considering effective treatment developments in gastric cancer. We studied 11 active co-operative groups, including six in Europe, two in the United States, and three in Japan, that have completed one or more phase III trials cited in the major guidelines. Each co-operative group had its own characteristics and contributed to the establishment of standard treatment in each region. International collaboration in the development of gastric cancer treatment may be difficult due to regional differences in standards of care, particularly for resectable gastric cancer. Whereas, intergroup collaboration within each region is a reasonable method to effectively develop treatments for resectable and advanced gastric cancer.