When to Test for Genetically Related Diseases
In the last issue of the Warde Report, Dr. Chottiner and I discussed the complex issue of testing for mutations in the BRCA1 and BRCA2 genes that are known to be associated with familial breast cancer.
Since the publication of that article, I have received some requests to clarify some of the issues that arise when performing this test. Will insurance companies pay for the test? How much of a risk for developing breast cancer is there if no mutation is found? What are the options for individuals who test positive for mutations in these genes?
There are now a huge number of mutations that have been reported with the BRCA1 and BRCA2 genes (more than 500). Therefore, the test for them is quite expensive because it requires extensive DNA sequencing. Some insurance plans do pay for this, whereas, others do not. The patients must contact their insurance carrier before testing to understand who must pay for the test.
Even if no mutation is found, the patient carries the same risk for the disease as other individuals in the general population. This is a lifetime risk of about 1 in 9 for breast cancer among women. Therefore, even individuals who test negative by the BRCA mutation analysis should have careful follow-up screening for breast cancer including: self-examination, professional examinations and mammography. Further, not all mutations are known, and a strong family history with a negative BRCA mutation study does not rule out an increased risk for an individual.
Although surgical (mastectomy and oophorectomy) and pharmacologic (tamoxifen) interventions are available for individuals who test positive for a BRCA mutation, they are not without hazard themselves and cannot guarantee freedom from future disease.
I recommend that an individual who is interested in obtaining BRCA or other genetic testing first meet with an oncologist or genetic counselor trained in the details of this complex and rapidly expanding medical area before embarking on testing. Included below is a list of individuals who may be useful to referring physicians or laboratories.
Please feel free to contact me directly at Warde Medical Laboratory if there are other questions about this testing.
David Keren, M.D. kerend@wardelab.com
Genetic Testing For Breast Cancer Additional Resources (1998) |