Ly Summary: BRCA testing is often requested for the purposes of testing relatives. It often makes sense to test the family member with the cancer first .
The common approach among those suspected of BRCA testing is to test a family member who is already diagnosed with breat or ovarian cancer. If a particular mutation is identified, a search for that mutation is indicated and sequencing of common variants or the entire gene is not necessary, which reduces costs. A negattive test decreases the possibility that a family member carries BRCA. It will not completely obviate the need for BRCA testing if there is high suspiction of it in a family member but makes it less likely and less necessary.
Most often, the first person that is tested in a family for BRCA-1 and BRCA-2 mutations is one who developed breast or ovarian cancer since this determines if the cancer in the family is associated with a BRCA mutation. If a mutation is found, it becomes a simple matter to test other blood relatives for the same mutation. If a mutation is not found in the family member who has or had cancer, the test is not informative and would not provide helpful information to other family members. If no family members with cancer are living or available for testing, testing options are generally considered on a case-by-case basis for each family. Testing may be appropriate in male relatives but only if it helps to identify female carriers in the family.
The benefit of testing is to the family member and coverage for that is the family mebmer’s responsibility and that of her plan.
U.S. Preventive Services Task Force (USPSTF). Genetic risk assessment and BRCA mutation testing for breast and ovarian cancer susceptibility: recommendation statement. Ann Intern Med 2005 Sep 6;143(5):355-61.
American Society of Clinical Oncology Policy Statement Update: Genetic Testing for Cancer Susceptibility. 11 April 2003. J Clin Oncol Accessed at www.asco.org/asco/downloads/GeneticTesting.pdf on 4 March 2005.