Evaluating the association between endometrial cancer and polycystic ovary syndrome

BACKGROUND: Given the current lack of clarity in the published literature, we performed a systematic review of the literature to determine the exact strength of the association between polycystic ovary syndrome (PCOS) and endometrial cancer (EC). METHODS: All published studies on the association between PCOS and EC identified through MEDLINE (1966-April 2011), EMBASE (1980-April 2011) and Cochrane (1998-April 2011). Original data were abstracted where available and summarized on a separate Microsoft Excel (2007) database for analysis. A total of 14 studies comparative and non-comparative were identified and included. RESULTS: The non-comparative and comparative data suggested that women with PCOS were more likely to develop EC. A meta-analyses of five comparative studies showed an increased risk of EC in women with an odds ratio of 2.89 with a 95% confidence interval of 1.52-5.48. CONCLUSIONS: Women with PCOS are about three times more likely to develop EC compared with women without it. This translates into a 9% lifetime risk of EC in Caucasian women with PCOS compared with 3% in women without it. Although most women (91%) with PCOS will not develop endometrial cancer, our study has shown that they are more likely at increased risk. More studies are required to clarify the exact molecular mechanisms, determine the best way of screening and preventing disease progression.