Evaluation of the Pathogenesis of Tumor Development from Endometriosis by Estrogen Receptor, P53 and Bcl-2 Immunohistochemical Staining

Objective: Endometriosis, one of the most common estrogen dependent gynecological disorders, can present as both benign and malignant disease. The prevalence of tumoral transformation is 0.7-1.6% and the most common tumors are clear cell and endometrioid carcinomas. Unfortunately, the pathogenesis of transformation is unknown. For this purpose, we examined molecular alterations in ovarian endometriosis and endometriosis-associated tumors. Methods: Using the data bank of Alzahra hospital pathology department and paraffin blocks from appropriate cases were identified. Sections were cut and stained for 3 markers: estrogen receptor, P53 and bcl2. Correlations between findings were investigated. Results: Nineteen cases of endometriosis-associated tumor and 19 cases of endometriosis were identified. Staining for bcl2 was documented in 14 of 19 (73.7%) of endometriosis-associated tumor cases and also 7 of 19 (36.8%) endometriosis cases (P=0.02). Only 3 of the 19 (15.8%) endometriosis-associated tumors exhibited positive staining for estrogen receptors, compared with 14 of 19 (73.7%) endometriosis cases (P<0.001). Positive staining for P53 was noted in 5 of 19 (31.6%) endometriosis-associated ovarian tumor samples but was absent in endometriosis samples (0%), (P =0.008). Conclusions: Endometriosis-associated tumors appear to be associated with overexpression of bcl2 and P53 and reduced expression of Estrogen receptor. These finding may help to diagnose tumoral transformation with a background of endometriosis.