Lack of association between cervical dysplasia and IBD: a large case-control study

It has been variously reported that women with inflammatory bowel disease (IBD) have an increased risk of cervical dysplasia. We aimed to assess in a large, accurately phenotyped, case-controlled population whether women with IBD had increased rates of abnormal cervical smears and if this was affected by immunosuppressant therapy or disease phenotype.

Women with IBD diagnosed prior to the age of 60 were studied at a single tertiary referral center in Scotland. Full cervical smear histories were available on 411 women (204 Crohn's disease, 207 ulcerative colitis, median age at diagnosis 28.4 years, median current age 44.1 years). All the cases were matched 1:4 to healthy controls (n = 1644) from the same geographical location.

There was no difference in rates of abnormal smears between patients with IBD (80.5% negative, 10.5% low-grade, and 9.0% high-grade dysplasia) and controls (85.4%, 7.7%, and 6.9%, P = 0.37). The use of immunosuppressant therapy had no impact on rates of cervical dysplasia or neoplasia. Furthermore, there was no effect of disease location, behavior, or oral contraceptive use. However, there were significantly more abnormal cervical smears in IBD patients who were current smokers compared with exsmokers and those who had never smoked (27.4% versus 11.4%, P = 0.001, odds ratio = 2.95, 95% confidence interval = 1.55-5.50).

Women with IBD are not at increased risk of abnormal cervical smears unless they smoke. These data suggest that young women with IBD should be managed as per the background population; attending for regular smear testing, and undergoing vaccination against cervical cancer when available.