COMPARISON OF SHAMS TEST FOR RECTAL MUCUS TO AN IMMUNOLOGICAL TEST FOR FECAL OCCULT BLOOD IN LARGE INTESTINAL CARCINOMA SCREENING - ANALYSIS OF A CHECK-UP OF 6480 ASYMPTOMATIC SUBJECTS

The sugar moiety detected from rectal mucus by the Galactose oxidase-s chiff (Shams' test) is considered a substitutive test for immunologica l fecal occult blood test (FOBT) in screening colorectal carcinoma. Tw o strategies of screening were applied in 6480 subjects over 40 years of age, and 130 cm flexible colonoscope used for sigmoidoscopy or panc olonoscopy. Of them, 3820 were taken for immune FOBT (SPA test) and Sh ams' test. Only those who showed positive tests were chosen for 60 cm flexible sigmoidoscopy, while another 2660 subjects for both sigmoidos copy and tests at the same dme. Additionally, 130 cm flexible pancolon oscopy %as carried out in 103 individuals with positive Shams' test fo r evaluating the false positive rate. Shams' test showed a sensitivity of 85.7% for colorectal cancer, 47.1% for adenomas in pre-selected pa tients, while the positive rate of SPA test were 90.5% and 41.2% respe ctively. In 3820 asymptomatic subjects undergoing sequential screening (aged 45 years and higher), Shams' test showed 9.1% positive, SPA sho wed 11.2% and 620(16.2%) subjects were selected for sigmoidoscopy base d on their positive galactose oxidase result or positive FOBT result. Two early stage carcinomas and 33 adenomas (0.32% and 4.2% respectivel y in sigmoidoscopy) were found. Another 2 660 subjects were taken for sigmoidoscopy screening. Four carcinomas and 78 adenomas were found. O f them, only two carcinoma (50%) and 17(21.8%) or 22(28.2%) adenomas w ere positive in Shams' or SPA test. But both tests combined in screeni ng showed a rate of 61.3% in adenomas and 75.0% in cancers. 103 subjec ts with positive Shams' test were taken for pancolonoscopy. 82.5% show ed no lesions. On these, we conclude that simple Shams' test can be re garded as a complementary test for immunological FOBT in screening col orectal carcinomas.