Outcomes for women in a flexible sigmoidoscopy-based colorectal cancer screening programme

Background: There are concerns that technical and anatomical factors can reduce the potential benefit of flexible sigmoidoscopy (FS) as a colorectal cancer (CRC) screening tool in women compared with men. Our aim was to review the outcomes for female participants in a community-based CRC screening project using FS.Methods: In 1995, a programme of unsedated FS-based screening of asymptomatic average-risk individuals aged 55-64 years was established at Fremantle Hospital, Western Australia. Insertion depths, pathological findings and site of adenomas and subject-rated pain scores have been prospectively recorded. Later diagnoses of malignancy were determined by linkage of the cohort with the West Australian Cancer Registry.Results: Between 1995 and 2005, 3402 primary screening FS examinations had been carried out (women 41%). Mean age of participants was 59.6 years. Women were more likely to undergo a FS with insertion depth less than 40 cm (17 vs 6%, P < 0.0001). Mean pain score was 2.9 for men and 4.0 for women (P < 0.0001). Women were less likely to have any neoplasia detected, independent of pain score or insertion depth (odds ratio 0.5, 95% confidence interval 0.4-0.6). Increasing insertion depth from 50 to 60 cm in a woman would only have a 0.4% chance of detecting any additional neoplasia. An insignificant trend to higher incidence of later interval CRC was observed in women with normal sigmoidoscopy.Conclusion: Women probably undergo FS with more discomfort and lesser insertion depth than men. It is unlikely that moderate increases in insertion depth would have a substantial benefit.