Why the BRCA-1 Gene increases the Risk of Breast Cancer
1. From Ramon Parsons of Columbia University
A. In breast cancer involving BRCA1, a second gene, called PTEN, plays a key role.
B. Scientists have known that BRCA1 normally repairs damage to other genes. If this gene is damaged by mutations, the unrepaired damage could be expected to lead to cancer.
C. The PTEN gene acts as a break to cancer growth.
D. Scientists have found that in breast cancers associated with BRCA1, PTEN is often broken and doesn't get repaired. That sets off a cascade that results in cancer.
E. Breast cancers associated with the BRCA1 gene are generally aggressive and have a poor prognosis. BRCA1 and BRCA2 account for less than 15% all breast cancers.