Risk of Cervical Cancer in Inflammatory Bowel Disease: A Meta-Analysis of Population-Based Studies.

INTRODUCTION

There is increased risk of several malignancies in inflammatory bowel disease (IBD). However, evidence regarding risk of cervical cancer in IBD is conflicting. We aimed to investigate the risk of cervical cancer in IBD by undertaking a systematic review and meta-analysis of unselected, population-based studies.

METHODS

MEDLINE, EMBASE, and Cochrane Library were searched using Medical Subject Heading terms, and 2 reviewers independently screened results. Pooled hazard ratios (HRs) were calculated using random effects model meta-analysis for risk of cervical cancer in IBD. Subgroup meta-analysis was undertaken to assess risk of cervical cancer by IBD subtype (Crohn's disease and ulcerative colitis), treatment exposure, and grade of lesion.

RESULTS

We screened 1,393 articles to identify 5 population-based studies, including 74,310 patients with IBD and 2,029,087 reference patients, across 5 different countries. Pooled random effects model meta-analysis of these studies did not show statistically significant increased risk for cervical cancer in IBD compared with reference populations (HR: 1.24; 95% confidence interval [CI]: 0.94-1.63). Meta-analysis by grade of lesion showed increased risk of low-grade cervical lesions (HR: 1.15; 95% CI: 1.04-1.28). Meta-analysis by disease subtype indicated no statistically significant increased risk in Crohn's disease (HR: 1.36; 95% CI: 0.83-2.23) or ulcerative colitis (HR: 0.95; 95% CI: 0.72-1.25) or in patients treated with antitumor necrosis factor (HR: 1.19; 95% CI: 0.64-2.21) or thiopurines (HR: 0.96; 95% CI: 0.60-1.50).

DISCUSSION

This meta-analysis of high-quality, unselected population-based studies shows no statistically significant increased risk of cervical cancer in patients with IBD. There is, however, increased risk of low-grade cervical lesions compared with the general population.