Ovarian endometriosis as a premalignant condition: epidemiological, histological and molecular evidence

Abstract Endometriosis is a common monoclonal benign proliferative disorder that may give rise to pelvic malignancy. Epithelial ovarian carcinoma is responsible for a large proportion of gynaecological cancer-associated deaths. Early diagnosis is difficult and screening is generally unsuccessful. Knowledge of the risk factors for the development of endometriosis and progression to malignancy may assist in identifying women at risk of developing endometriosis-related neoplasia. The associations between infertility, endometriosis and the development of cancer are reviewed in this article. Proliferative growth, metaplasia, hyperplasia and atypia are identified as proliferative disorders in endometriosis and atypia is considered a premalignant lesion. Several endometriosis-related pelvic malignancies have been described, and these all develop from the multipotent Mullerian cell differentiating into epithelial and/or stromal components. The probable histological type depends on the site of the endometriotic lesion and the population group. Cytogenetic and specific gene alterations that are involved in the carcinogenetic process are described briefly and these may help to predict risk of malignancy or to confirm histological subtype. The importance of endometriosis as a precursor of ovarian and related malignancies was probably seriously underestimated in the past. Advances in molecular testing, histology and our understanding of oncogenesis may empower us to help prevent these devastating diseases.