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

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.

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.

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.

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.