21. Risk of cervical dysplasia and cancer in patients with inflammatory bowel disease
C. Rungø1, J. Simonsen2, L. Riis3, M. Frisch1, E. Langholz4, T. Jess1, 1Statens serum institute, Department of Epidemiology and Research, Copenhagen, 2Statens Serum Institute, 3Herlev Hospital, 4Gentofte Hospital, Denmark
Whether patients with inflammatory bowel disease are at an increased risk of cervical neoplasia remains unclear. We examined if female Danish patients with ulcerative colitis (UC) or Crohn's disease (CD) had a higher risk of receiving a diagnosis of cervical dysplasia or invasive cervical cancer and/or higher screening intensity than women in the background population.
By combining data from Danish national registers we conducted a matched-cohort study on 20,542 female patients with UC and 9,466 patients with CD, diagnosed in Denmark from 1977–2011, compared with 1,508,334 individually age- and geography-matched control women from the general population.
Dysplasia was divided into “mild-to-low-grade” and “moderate-to-high-grade”, the latter including carcinoma in situ in accordance with the Bethesda classification. Cancer was defined as “primary cancer of cervix uteri”. Risk of dysplasia or cancer was estimated by stratified Cox regression analysis and results are presented as hazard ratios (HRs) with 95% confidence intervals.
Using Poisson regression we estimated the average cervical cancer screening rate ratio (RR) in UC and CD patients compared to that of women in the background population.
Screening activity was inconspicuous in women with CD (RR= 0.99; 95% CI: 0.95–1.03), but slightly increased in patients with UC (RR= 1.06; 95% CI: 1.03–1.09). For CD patients, risks of mild-to-low-grade (HR= 1.40; 95% CI: 1.22–1.61) or moderate-to-high-grade (HR= 1.25; 95% CI; 1.11–1.41) dysplasia were significantly increased, but this was not the case in UC patients (HR = 1.11; 95% CI; 0.97–1.26 for mild-to-low-grade; HR= 1.08; 95% CI: 0.97–1.20 for moderate-to-high-grade). Accordingly, risk of invasive cervical cancer was increased in CD patients (HR = 1.51; 95% CI: 1.08–2.13) but not in UC patients (HR = 0.78; 95% CI: 0.57–1.08). Risk of invasive cervical cancer increased with time since CD diagnosis, being 84% increased after 10 years (HR = 1.84; 95% CI: 1.12–3.04).
In this nationwide study of UC and CD patients followed over a 35-year period, we show that women with CD are at increased risk of cervical dysplasia and invasive cervical cancer despite similar screening intensity as in the general population. No increased risk of cervical neoplasia was seen in patients with UC.