Abstract
The merits of Hemoccult II testing (guaiac test slides of stool specimens obtained in three days) for use in screening for colorectal cancers were evaluated and compared with the results obtained for Hematest, and the FECATWIN-S and FECA-EIA test. Hemoccult II testing was positive in 93.1% of 72 cases of advanced colorectal cancers, and even in 47% of 15 cases of "early" colorectal cancers in which invasion was limited to the mucosa and submucosa. However, positive results were also obtained for cases of functional gastrointestinal disorders, i. e., in 19.2% of 679 cases of irritable colon or simple constipation and in 13.5% of 1, 023 cases of "chronic gastritis". Furthermore, positive results were also obtained in 14.8% of 318 patients with diseases of the liver, biliary tract or pancreas, in which the gastrointestinal tract was thought to be intact. Thus, the false-positive rate for Hemoccult II testing was thought to range from approximately 13.5% to 19.2%. In addition, the technique of Hemoccult II testing was much easier and cheaper in price compared with FECATWIN-S and FECA-EIA test and lower in false positive rate compared with Hematest. Accordingly, Hemoccult II testing is presently considered to be useful for the screening of colorectal cancers.
