Chemical and immunological testing for faecel occult blood: a comparison of two tests in symptomatic patients.
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.
Thomas
W M
WM
Department of Surgery, University Hospital, Nottingham, UK.
Hardcastle
J D
JD
Jackson
J
J
Pye
G
G
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