The genetic basis of hereditary breast and ovarian cancer (HBOC) is a germline mutation in highly penetrant cancer susceptibility genes such as BRCA1 and BRCA2. Normally the proteins encoded by BRCA1 and BRCA2 genes prevent cells from becoming malignant by helping to repair mutations that occur in other genes - making them "tumor suppressor genes." But an inherited mutation within either of these tumor suppressor genes greatly increases the probability of malignant transformation and cancer.
The reason that mutations in BRCA1 and BRCA2 are associated primarily with cancers of the breast and ovary is not yet fully understood, but is thought to be related to the expression of estrogen receptors in these tissues.
Specifically, approximately seven percent of breast cancer cases and 10 percent of ovarian cancer cases are thought to be associated with an autosomal dominant pattern of inheritance of BRCA1 and BRCA2 gene mutations.8 When assessing hereditary cancer risk, a patient's comprehensive family history remains an essential part of investigating the risk of HBOC. However, genetic testing provides the most accurate risk assessment profile for HBOC.
View mutation prevalence tables for BRCA1 and BRCA2 genes.
» Identifying Patients at Risk for HBOC
A genetic test for hereditary breast and
ovarian cancer
