Progress in the treatment of gastric cancer in Japan over the last 50 years.

There have been remarkable changes in gastric cancer treatments in Japan, resulting in superb improvement of prognosis in patients with this disease. In this paper, the last 50 years have been divided into three eras: before 1990; the 1990s; and the era of evidence, which means after 2000. Changes of treatments and prognosis were analyzed by several factors, such as surgery, chemotherapy, informed consent, clinical trials, and others, as improvement of prognosis is not due to one factor but several ones influencing each other.