Malignant transformation of endometriosis and genetic alterations of K-ras and microsatellite instability

Objectives: To clarify the role of specific genetic alterations in the multi-step process of malignant transformation of endometriosis. Methods: In cases of ovarian endometrioid carcinoma, we separated regions of normal endometriosis, atypical endometriosis and ovarian endometrioid carcinoma by laser microdissection, and examined K-ras mutation and microsatellite instability in each separated tissue sample. Results: We detected K-ras mutation and microsatellite instability in endometrioid carcinoma tissue, but not in normal or atypical endometriosis bordering the cancerous region. Conclusions: The present findings suggest that K-ras mutation and microsatellite instability are associated with malignant transformation from atypical endometriosis to ovarian endometrioid carcinoma.