Cancer Causes Control 2017 May 24;28(5):415-428. Epub 2017 Mar 24.
Faculty of Medicine, School of Public Health and Primary Care, The Chinese University of Hong Kong, Room 508, 5/F, School of Public Health, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China.
Purpose: Previous studies on pelvic inflammatory disease (PID) and the risk of ovarian cancer have found inconsistent results. We performed an updated meta-analysis to summarize the evidence of this association.
Methods: PubMed, Embase, and ISI web of science databases were searched through October 2016 for studies that investigated the PID and ovarian cancer association. Summary risk estimates were calculated using random-effects meta-analysis.
Result: Thirteen studies were eligible for analysis, which included six cohort studies and seven case-control studies. PID was associated with an increased risk of ovarian cancer overall [relative risk (RR) 1.24, 95% CI 1.06-1.44; I = 58.8%]. In analyses stratified by race, a significant positive association was observed in studies conducted among Asian women (RR 1.69, 95% CI 1.22-2.34; I = 0%), but marginally significant among Caucasians (RR 1.18, 95% CI 1.00-1.39; I = 60.7%).Risk estimates were elevated in both cohort (RR1.32; 95% CI 1.05-1.66; I = 64.7%) and case-control studies (RR 1.17; 95% CI 0.93-1.49; I = 57.6%), albeit not statistically significant in case-control studies.
Conclusions: Our results suggested that PID might be a potential risk factor of ovarian cancer, with pronounced associations among Asian women. Large and well-designed studies with objective assessment methods, such as hospital records, are needed to confirm the findings of this meta-analysis.