title: Chemical and immunological testing for faecel occult blood: a comparison of two tests in symptomatic patients.
abstract: An established chemical faecal occult blood test (Haemoccult prepared without rehydration) has been compared with a new immunological test (Hemeselect) in patients referred for investigation of lower gastro-intestinal symptoms. Hemeselect was shown to have a higher sensitivity for colorectal carcinoma (94.0% compared with 58.0%), the greatest difference in sensitivity between the two tests being for rectal cancers. Similarly Hemeselect was more sensitive than Haemoccult for colorectal adenomas (66.6% vs 33.3%), and for inflammatory bowel disease (88.9% vs 33.3%). However the enhanced sensitivity of Hemeselect for colorectal neoplasia and inflammatory bowel disease was accompanied by a significant increase in the overall rate of positive reactions (32.8% of patients had a positive Hemeselect reaction compared with 14.8% who had a positive Haemoccult test), and a reduction in specificity (84.1% for Hemeselect vs 96.0% for Haemoccult). Hemeselect is a more sensitive indicator of colorectal neoplasia in symptomatic subjects, trials of its use as a screening test for asymptomatic neoplasia appear justified.
authors.affiliation: Department of Surgery, University Hospital, Nottingham, UK.
authors.forename: W M
authors.initials: WM
authors.lastname: Thomas
authors.forename: J D
authors.initials: JD
authors.lastname: Hardcastle
authors.forename: J
authors.initials: J
authors.lastname: Jackson
authors.forename: G
authors.initials: G
authors.lastname: Pye
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D006801:Humans; D007158:Immunologic Techniques; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis; D008875:Middle Aged; D009780:Occult Blood