Outcomes after 10 years of a community-based flexible sigmoidoscopy screening program for colorectal carcinoma.

OBJECTIVE: To evaluate the outcomes 10 years after a flexible sigmoidoscopy colorectal cancer (CRC) screening program in asymptomatic average-risk individuals.

DESIGN, SETTING AND PATIENTS: In 1995, a program of flexible sigmoidoscopy-based screening of asymptomatic average-risk individuals aged 55-64 years was established at Fremantle Hospital, Western Australia. Insertion depths, pathological findings and subject-rated pain scores have been prospectively recorded. A follow-up flexible sigmoidoscopy examination was offered to attendees 5 years after the initial screening. Post-screening malignancies were determined by linkage with the Western Australian Cancer Registry in September 2006.

MAIN OUTCOME MEASURES: Yield of neoplasia at initial and follow-up sigmoidoscopy, and the incidence of CRC detected after screening.

RESULTS: Between 1995 and 2005, 3402 people underwent an initial flexible sigmoidoscopy screening examination (mean age, 60 years; women, 41%) and 1025 had a 5-year recall examination. Mean insertion depth was greater in men than women (60 cm v 52 cm, P<0.001). The insertion depth in women was more likely to be <40 cm (17% v 6%, P<0.001). Mean pain score was 2.9 for men and 4.0 for women (P<0.001). Fourteen per cent of initial screenings detected at least one adenoma. Over a mean follow-up time of 8 years, invasive CRC was detected by flexible sigmoidoscopy screening in 0.4% of participants; 0.7% of those with a normal result of screening later developed CRC, with 75% of these found proximal to the splenic flexure.

CONCLUSIONS: Flexible sigmoidoscopy is a viable screening method, with well defined utility and limitations, for CRC screening of asymptomatic people with average risk.