A comparison of an immunological faecal occult blood test Fecatwin sensitive/FECA EIA with Haemoccult in population screening for colorectal cancer.

Two faecal occult blood tests, a simple chemical test Haemoccult and an immunological test, Fecatwin Sensitive/Feca EIA, were offered to 3,225 asymptomatic individuals as screening for colorectal cancer. One thousand three hundred and four (44%) completed and returned the tests and of these 126 (9.7%) were found to be positive - Haemoccult 40 (3%) and Feca EIA 106 (8.1%). Five cancers (4 Dukes' Stage A, 1 Dukes' Stage C) and 23 adenomas greater than 1 cm were detected - rates of 3.8 per 1000 persons screened and 17.7 per 1000 persons screened respectively. Of the five cancers identified 5 were Feca EIA positive and 3 were Haemoccult positive. Of the 23 adenomas greater than 1 cm diameter identified, J1 were Feca EIA positive and 20 were Haemoccult positive. Seventy-eight Feca EIA positive subjects were investigated and no neoplastic disease was identified. Whilst this sensitive immunological test increases the yield of carcinomas, the high false positive rate makes it unsuitable for population screening for colorectal cancer in its present form.