Steroid receptors, HER2/neu and Ki-67, in endometrioid type of endometrial carcinoma: Correlation with conventional histomorphological features of prognosis

Endometrial proliferation is regulated by steroid receptors such as estrogen receptor alpha (ERα), estrogen receptor beta (ERβ) and progesterone receptor (PR). HER2/neu is an important growth factor receptor which affects cell proliferation and Ki67 is a marker of cellular proliferation. Their interaction in endometrioid type of endometrial carcinoma is still not fully understood. In this study, we analyzed the immunolocalisation of ERα and ERβ with particular attention to the ERβcx isoform, PR, HER2/neu and Ki67 in endometrioid carcinoma. Their correlations with each other and with the conventional morphological prognostic parameters of myoinvasion and tumor grade were analyzed with respect to overall survival. Out of a total 54 cases, 14 showed evidence of local recurrence or metastatic disease within 5 years with poor outcome, whereas the rest had no evidence of disease. ERα, ERβ, ERβcx, PR, HER2/neu and Ki67 were detected using immunohistochemistry. The histological grade of the tumor correlated inversely with the intensity of immunolabelling of ERα and PR, and this was highly significant. The depth of myoinvasion showed an inverse correlation only with the ERβ2/βcx immunopositivity and was not significantly associated with any other receptor evaluated. Analysis of the inter-relationship between receptor immunopositivity revealed a significant association of ERα immunolocalisation with ERβ and with PR. Immunodetection of HER2/neu receptor correlated positively with both ERα and PR immunolabelling. The Ki-67 proliferation index correlated only with ERα immunopositivity. Preliminary observations suggested that with the exception of ERα, there was no correlation of any of the receptors evaluated with survival.