PTEN as a predictive marker of response to conservative treatment in endometrial hyperplasia and early endometrial cancer. A systematic review and meta-analysis

OBJECTIVE: Several markers have been studied to predict the responsiveness of endometrial hyperplasia (EH) and early endometrial cancer (EEC) to progestin therapy. PTEN has played a major role in this field, although its predictive significance is still undefined. We aimed to assess if loss of PTEN expression on pre-treatment endometrial specimen may be a predictive markers of response to progestins in EH and EEC. STUDY DESIGN: MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID and Cochrane Library were searched for relevant articles from the inception to May 2018. All studies assessing PTEN expression as predictive marker in EH and EEC treated with progestin were included. Relative risk (RR) for therapy failure was calculated with 95% confidence interval (CI) and a significant p-value<0.05, with a subgroup analysis based on the histologic category (EEC or EH) and the administration route of progestin (oral or intrauterine). RESULTS: Seven cohort studies assessing 376 patients were included. PTEN loss was not significantly associated with the outcome of therapy in the overall analysis (RR = 1.24, 95% CI, 0.88-1.76, p = 0.21), in + the subgroups of EEC (RR = 0.89, 0.32-2.49, p = 0.83), EH (RR = 1.30, 0.90-1.87 p = 0.16), oral progestin (RR = 1.25 0.88-1.79, p = 0.22) and intrauterine device (RR = 1.02, 0.36-2.87, p = 0.97). CONCLUSION: PTEN seems not to be useful as predictive marker of response to the conservative treatment of EH and EC, regardless of the administration route (oral or intrauterine) of progestins. We advise future researcher not to further assess PTEN as a stand-alone predictive marker.