Abstract
X-ray examination has been widely applied in gastric cancer screening all over Japan. However, on some small islands of the Okinawa Archipelago, this procedure has been impossible to carry out for technical reasons. Therefore, since 1981, the gastrointestinal department of the University of the Ryukyus Hospital has conducted endoscopic examinations in gastric cancer screenings in order to contribute to the health care of the residents of those islands and the epidemiological and clinical studies of gastric cancer mass screening.
We performed 7,082 endoscopic examinations for a total of 6,444 residents on 9 islands in gastric cancer mass screenings conducted from 1981 to 1989. During this period, we diagnosed 6 cases of esophageal cancer and 18 cases of early gastric cancer. Notably, in our work on Yonaguni Island, we diagnosed 7 cases of gastric cancer over a period of 5 years of endoscopic mass screenings, whereas no case of gastric cancer was identified within the subsequent 8 years of X-ray mass screenings.
Colorectal cancer mass screenings have been conducted in Japan since 1992, but they were not performed on the Yaeyama Islands until 1996 because of the insufficient supply of equipment and personnel required for colonoscopic examinations. Therefore, we performed thorough colonoscopic examinations for 180 examinees over the course of 5 weekends, and identified 23 cases of colorectal cancer, including 11 cases of early cancer.
These results clearly indicate that endoscopic examination in gastrointestinal cancer mass screenings has contributed to the health of the residents of a region where X-ray mass examination is not easily accessible. On the other hand, since the consultation rate for cancer mass screenings and detailed examinations is still low, improving the consultation rate is the most important nation-wide challenge today.
