Finding colorectal tumours with an immunological faecal occult blood test in symptomatic primary health care patients.

The aim of this prospective study was to investigate whether an immunological double faecal occult blood test (Fecatwin-S/FECA-EIA) can be used in screening patients with symptoms suggestive of colonic or rectal origin in primary health care. Altogether 523 patients were referred to the study by general practitioners. Three kits were used for the faecal samples and each time the sample was taken from two places of the faeces. If the guaiac test (Fecatwin-S) was positive, the immunological test (FECA-EIA) was performed. All 71 patients with an immunotest absorbance value of over 0.8 were investigated with colonoscopy and this group had 13 cancers, eight adenomas and one hyperplastic polyp. A control group of 41 consecutive patients with an absorbance value under 0.8 had one adenoma and three hyperplastic polyps. The uninvestigated FECA-EIA negative patients had no malignant colorectal tumours in the mean follow-up period of 2.2 years according to hospital records. All cancers had very high absorbance values, the mean value being 2.461. With adenomas the mean absorbance value was 1.912 and with hyperplastic polyps 0.814. Most of the diagnosed cancers and adenomas were in patients over 65 years of age. The study indicates that the immunological occult blood test is a useful tool for a general practitioner in finding bleeding colorectal tumours. The number of needless clinical examinations can be lowered which is important especially among elderly patients. However, the test-negative patients should be retested or investigated if symptoms continue.