Objective: To test a pilot screening program for colorectal cancer.
Design: Subjects, chosen at random and recruited by mail, were examined by flexible sigmoidoscopy.
Participants and setting: Normal-risk, asymptomatic men and women aged 55-59 years recruited from the community, July to December, 1995.
Main outcome measures: Number of polyps detected and cancers diagnosed, and compliance with screening.
Results: Letters of invitation were sent to 3500 subjects; of these, 2881 were eligible for inclusion in the study and 342 (12%) consented to participate. A further 3.5% of non-compliant subjects attended the screening program after a telephone survey assessing reasons for non-attendance. Common reasons for non-attendance were a lack of interest (30%) or a lack of time, mainly due to work commitments (28%). A third of subjects had polyps and 46% of these were adenomas. Three subjects were found to have adenocarcinoma: in two the cancer was confined to a polyp and treated with polypectomy, and one subject underwent anterior resection (overall prevalence of cancer, 0.9%). The median depth of insertion achieved with flexible sigmoidoscopy was 55 cm (range, 25-100 cm). Median pain level (on a scale of 0 = no pain to 10 = worst pain imaginable) was 2 (range, 0-8.5), and 99% of the subjects would have the test again if required.
Conclusions: Flexible sigmoidoscopy was well tolerated and had an acceptable detection rate of adenomatous polyps and early cancer. Subject compliance emerged as a major issue which requires further evaluation to maximise participation in future programs.