Community screening for colorectal cancer in north-eastern New South Wales, 1987-1996

OBJECTIVE: To analyse results of Bowelscan, a community-based colorectal cancer screening program using Hemoccult II, and targeting people aged 40 years and over. DESIGN: Survey of data from medical practitioners on follow-up of positive tests. SETTING: North-eastern New South Wales (Rotary District 9650), 1987-1996. SUBJECTS: 3845 people with positive results for faecal occult blood. OUTCOME MEASURES: Investigations performed; final diagnoses; number, site and Dukes' stage of colorectal carcinomas; number and histological diagnosis of colorectal polyps. RESULTS: 239,500 Hemoccult II kits were distributed between 1987 and 1996, with an estimated return rate of 80%-85%. Positive results for faecal occult blood were reported for 3845 tests (1.6% of those distributed), with 78% of these investigated by colonoscopy and/or barium enema. Investigation resulted in diagnosis of 260 colorectal carcinomas in 252 people (6.7%); 74 of these (29%) were in the caecum or ascending or transverse colon. Dukes' tumour stages were: A, 107 (41%); B, 86 (33%); C, 49 (19%); D, 16 (6%); and unknown, 2 (0.8%). (Corresponding figures from the NSW Central Cancer Registry were: A and B, 48%; C, 26%; D, 14% and unknown 12%) [corrected]. Colorectal polyps were found in a further 819 people (21.3%), and were adenomatous in 577 (79% of the 733 in whom histological diagnosis was available). Other gastrointestinal conditions were found in 1343 people (34.9%), while no cause was found for the positive result, despite adequate investigation, in 873 (22.7%). CONCLUSION: Community-based screening with faecal occult blood testing detected colorectal carcinomas at earlier histological stages than colorectal carcinomas reported to the Cancer Registry and should reduce mortality from this disease. Treatment and follow-up of adenomatous polyps detected by such a program might minimise the incidence of colorectal carcinoma in this group.