Promoter Hypermethylation and BRCA1 Inactivation in Sporadic Breast and Ovarian Tumors

Silencing of the BRCA1 gene by promoter hypermethylation occurs in primary breast and ovarian carcinomas, especially in the presence of LOH and in specific histopathologic subgroups. These findings support a role for this tumor suppressor gene in sporadic breast and ovarian tumorigenesis.