Common genetic changes between endometriosis and ovarian cancer.

We analyzed 81 ovarian cancers for loss of heterozygosity (LOH) on 10q23 and for mutations in PTEN. LOH was common among the endometrioid (43%) and serous (28%) cancers, but was infrequent among the other histological subtypes. Somatic PTEN mutations were detected in seven (21%) endometrioid cancers and the mutation in all informative cases was accompanied by loss of the wild-type allele. One mucinous cancer without 10q23 LOH was shown to harbor two somatic PTEN mutations. Frequent LOH was observed on chromosome 6q (60.0%) and chromosome 10q (40.0%) in ovarian atypical endometriosis, but no PTEN mutations were observed. These findings support the hypothesis that endometrioid and clear cell ovarian carcinomas may arise through malignant transformation of endometriotic lesions.