Immunohistochemical predictive markers of response to conservative treatment of endometrial hyperplasia and early endometrial cancer: A systematic review

INTRODUCTION: Progestogens are widely used for the conservative treatment of endometrial hyperplasia and early endometrial cancer. Nevertheless, they do not achieve the regression in all cases. Although several immunohistochemical markers have been assessed to predict the response to treatment, their usefulness is still unclear. We aimed to analyze the usefulness of each immunohistochemical marker studied in predicting the response to progestogens in endometrial hyperplasia and early endometrial cancer. MATERIAL AND METHODS: Electronic databases were searched for relevant articles from January 2000 to June 2018. All studies assessing the association of immunohistochemical markers with the outcome of the progestogen-based therapy in endometrial hyperplasia and early endometrial cancer were included. The expression of immunohistochemical markers in pretreatment phase and changes of expression during the follow-up were evaluated in relation to response to therapy and relapse. RESULTS: Twenty-seven studies with 1360 women were included in the systematic review; 43 immunohistochemical markers were assessed. The most studied predictive markers in the pretreatment phase were progesterone and estrogen receptors, although with conflicting results; their isoforms, and in particular progesterone receptor B, appeared more promising. Further studies are needed to confirm the usefulness of mismatch repair proteins, Dusp6, GRP78 and PTEN combined with other molecules such as phospho-AKT or phospho-mTOR. In the follow-up phase, Nrf2 and survivin showed the stronger evidence; a role may also be played by Bcl2 and Ki67. Further studies are necessary for Fas, NCoR, AKR1C1, HE4, PAX2 and SPAG9. CONCLUSIONS: Several immunohistochemical markers might be helpful in predicting the response to conservative treatment of endometrial hyperplasia and early endometrial cancer on pretreatment and follow-up specimens. Further studies are needed to confirm their usefulness and possibly integrate them in a predictive immunohistochemical panel.