Abstract
Colorectal cancer has been increasing in Japanese in contrast with the decline of gastric cancer and such a screening system simulating the stomach mass survey should be established as soon as possible. In USA and European countries, fecal occult blood test, hemoccult test, is widely applied to the colon mass survey, but it is not enough evaluated in Japan. Using both methods of guaiac test and hemoccult test, we examined 319 patients consisting of 67 with advanced cancer, 6 with early cancer, 126 with benign polyp and 120 controls without any gastrointestinal diseases. All cases of advanced cancer and 4 of early cancer (66.7%) showed a positive guaiac test, while 1.5% of advanced cancer and 50% of early cancer showed a negative hemoccult test. Positive rate in benign polyp correlated with its size and 41.3% and 23.0% were positive by the guaiac test and by the hemoccult test respectively. On the other hand, the false positive rate in the controls was 7.7% by the guaiac test and 2.6% by the hemoccult test under restriction of meat and fish, but it increased to 28.6% by the guaiac test and 7.1% by the hemoccult test without the restriction. Thus, the guaiac test was more sensitive than the hemoccult test. Although cancer could be diagnosed in its curative stage also by the hemoccult test, the guaiac test is better for the earlier screening if the diet restriction is kept.
