Genetic Mutation Ups Risk for Contralateral Breast Cancer
Women with BRCA1, BRCA2 mutations have 4.5-fold, 3.4-fold increased risks, respectively
TUESDAY, April 6 (HealthDay News) -- Women who carry a BRCA1 or BRCA2 genetic mutation and develop breast cancer are at a substantially increased risk for contralateral breast cancer later on, according to research published online April 5 in the Journal of Clinical Oncology.
Kathleen E. Malone, Ph.D., of the Fred Hutchinson Cancer Research Center in Seattle, and colleagues conducted a nested case-control study in which 705 women with contralateral breast cancer diagnosed a year or more after first primary breast cancer, and 1,398 controls with unilateral breast cancer, were ascertained from a cohort of 52,536 women diagnosed with a first invasive breast cancer before the age of 55 years.
The researchers found that women who carried the BRCA1 and BRCA2 mutation had a 4.5-fold and 3.4-fold increased risk, respectively, of developing contralateral breast cancer compared with non-carriers. In addition, the relative risk of contralateral breast cancer for BRCA1 carriers increased as the age of first diagnosis decreased.
"The risks of subsequent contralateral breast cancer are substantial for women who carry a BRAC1/BRAC2 mutation," the authors write. "These findings have important clinical implications in terms of the potential value of BRCA1/BRCA2 testing in patients with early-onset breast cancer as well as therapeutic, preventive, and surveillance considerations for patients found to carry a mutation."