Endometriosis and ovarian cancer: a review.

OBJECTIVES To describe the relationship between endometriosis and ovarian cancer. SEARCH STRATEGY Review of the relevant clinical, epidemiologic, and molecular biology literature. SELECTION CRITERIA Studies published in the English language using the MEDLINE database. DATA COLLECTION AND ANALYSIS Relevant studies were reviewed by the three authors and those that seem to be of significant scientific value, based on the methodology and statistical power, were included. MAIN RESULTS Endometriosis and ovarian cancer share many common predisposing factors. Both conditions demonstrate similar patterns regarding local invasion and distal spread they respond similarly to estrogen-induced growth signaling, they express resistance to apoptotic mechanisms and they are characterized by genomic instability. Endometrioid and clear-cell are the most frequent types of ovarian cancer associated with endometriosis. Tubal ligation, in women with endometriosis, seems to prevent retrograde menstruation but it has also been shown to be protective from these types of ovarian cancer. CONCLUSION There is evidence to support that endometriosis (by definition a benign process), could simultaneously have the potential for malignant transformation. More studies are needed to establish risk factors that may lead to malignant transformation of this condition and to identify predisposed individuals who may require closer surveillance.