Is oral contraceptive use associated with an increased risk of cervical cancer? An evidence-based meta-analysis

Aim: The purpose of this meta-analysis is to synthesize evidence-based case-control studies to evaluate the association between oral contraceptive (OC) use and the risk of cervical cancer. Methods: Two reviewers independently selected potentially relevant studies through PubMed, Embase, Chinese National Knowledge Infrastructure, Wanfang Data, and the Chongqing VIP databases using the core terms cervical intraepithelial neoplasia/ cervix dysplasia/ cervi* AND oral contraceptive in the article titles, abstracts, and keywords. All data were analyzed using STATA 12.0. The heterogeneity was assessed by Q-test and I-2 statistic. Forest plot was used to display results graphically. Publication bias was assessed by Begg's test. Results: In total, 16 case-control studies, including 15 619 participants (7433 cases and 8186 controls), met the eligibility criteria. Individuals with OC use were not found to have a risk of cervical cancer (odds ratio [OR], 1.12; 95% confidence interval [CI], 0.90-1.38). In subgroup analyses, no significant associations were found for different durations of OC use (<5 years: OR, 0.84; 95% CI, 0.68-1.04; 5-10 years: OR, 1.06; 95% CI, 0.66-1.71; >10 years: OR, 1.25; 95% CI, 0.76-2.06). Additionally, using OC was not shown to increase the risk of cervical cancer among women with human papillomavirus infections (OR, 1.09; 95% CI, 0.80-1.49). However, an increased risk of cervical cancer was found in Asian populations with OC use. Conclusion: The meta-analysis of case-control studies did not show an association between OC use and risk of cervical cancer. However, other necessary prospective cohort studies should be conducted to assess the impact of OC use on cervical cancer risk in the future.