Pelvic Inflammatory Disease and Risk of Ovarian Tumor: A Meta-analysis

Objective To systematically assess the relationship between pelvic inflammatory disease(PID) and the risk of ovarian tumor．Methods We searched the cohort or case-control studies in PubMed, EMbase, The Cochrane Library, CBM, CNKI and WANFANG(from inception to Oct, 2013). Meta-analysis was performed by RevMan 5.2 software, to assess OR and 95%CI of involved cohort and case-control studies. Results Two cohort studies and eight case-control studies were included. Meta-analysis on cohort studies showed PID could increase the risk of ovarian tumor(OR=1.72, 95％CI:1.17-2.52, P=0.006)．Besides, Metaanalysis of case-control studies showed PID was not associated with the incidence of ovarian tumor (OR=1.07, 95％CI :0.86-1.33, P=0.55). However, two studies found that recurrent PID could increase the risk of ovarian cancer. Conclusion Meta-analysis of cohort studies and case-control studies are inconsistent. However, the risk of ovarian tumor is increased with PID exposure. Because of the limited quantity of case-control studies and too few cohort studies, it needs to develop more high-quality prospective studies to further validate these results, especially about the risk relationship between recurrent or chronic PID and ovarian tumor.