The association between endometriosis and ovarian cancer: a review of histological, genetic and molecular alterations

OBJECTIVE: This article represents a review of histologic and genetic findings in endometriosis and describes the mechanisms whereby genetic and non-genetic factors potentially contribute to the neoplastic progression of endometriosis. METHODS: Literature review of the English language literature based on searching in the MEDLINE (PubMed) database and additional collection of reports by systematically reviewing all references from retrieved papers. RESULTS: Atypical endometriosis seems to represent a transition from benign endometriosis to carcinoma. Endometriosis is characterized by genetic instability: like neoplasms endometriosis seems to be monoclonal in origin, several studies have documented loss of heterozygosity (LOH) in endometriosis, data suggest that mutation of the tumor suppressor gene PTEN play a part in the malignant transformation of endometriosis, some studies have revealed TP53 mutations in endometriotic lesions, and mutation of ARID1A seems to be an important early event in the malignant transformation of endometriosis to endometrioid and clear cell carcinomas. Heme and iron induced oxidative stress, inflammation, and hyperestrogenism are possible links between endometriosis and cancer. CONCLUSIONS: The histological and genetic alterations in endometriosis seem to explain why endometriosis can be a precursor of some ovarian cancers, especially clear cell and endometrioid carcinomas. However, the exact molecular mechanisms that may lead to this malignant transformation of endometriosis are not completely understood. More and larger studies are needed to clarify how exactly endometriotic tissue undergoes malignant transformation.