Impact of endometriosis on risk of ovarian, endometrial and cervical cancers: a meta-analysis

PURPOSE: The risks of gynecologic cancer have not been well established in women with endometriosis. The objective of the present study was to investigate the influence of endometriosis on the risk for three gynecologic cancer (ovarian cancer, endometrial cancer and cervical cancer). METHODS: We gathered updated evidence about the risk relationship between endometriosis and gynecologic cancers by conducting a comprehensive search of several medical literature electronic databases, including PubMed, Embase and the Cochrane Library. The design and quality of all studies were evaluated using the Newcastle-Ottawa Scale (NOS), and a random-effects model was used to calculate pooled risk ratio (RR). RESULTS: Of the 8538 articles our search produced, we selected 25 qualified studies, including 16 cohort studies and 9 case-control studies. Patients with endometriosis had both an increased risk of ovarian cancer [RR  1.964; 95% CI (1.685, 2.290)]. The risk of endometrial cancer (EC) is not necessarily higher in patients with endometriosis [RR 1.176, 95% CI (0.878, 1.575)]. Endometriosis was not associated with an increased risk for cervical cancer (CC) [RR 0.670, 95% CI (0.537, 0.838)]. CONCLUSIONS: Patients with endometriosis need to be closely observed and rechecked regularly to prevent malignant changes.