Any physician can order a genetic test; but genetic counselors are specially trained to discuss whether it makes sense for you to be tested (it’s not right for everyone). After testing, a qualified genetic counselor can interpret your results, estimate your risk, and if appropriate, discuss risk management strategies.
A genetic counselor’s input can be particularly important involving variants of uncertain significance (VUS), changes that occur in a gene, but whether that change is harmful and interferes with the gene’s normal tumor-suppressing ability and therefore raises the risk of breast cancer, is unknown. Unlike a test result that shows a clear indication of a genetic mutation, a VUS doesn’t provide a clear answer about an individual’s risk.
A study published earlier this year by researchers at Stanford University School of Medicine, University of Southern California, Emory University and Memorial Sloan-Kettering Cancer Center underscores the important role of genetic counselors, particularly involving risk management strategies for VUS.
When researchers surveyed 2,500 newly diagnosed breast cancer patients and the surgeons who treated them, they discovered that many of the women had potentially unnecessary mastectomies, perhaps because they and their doctors didn't understand how to interpret genetic test results:
- Only about half of the women who had genetic testing discussed their results with a genetic counselor. (Surgeons and oncologists ordered most of the tests; only about 1 in 5 was ordered by a genetic counselor.)
- 50% of surgeons who saw 0-20 new breast cancer patients in the past year and 24% of surgeons who saw 50 or more new breast cancer patients in the past year reported that they were less confident discussing genetic testing results with patients, and recommended the same treatment—bilateral mastectomy—for women with VUS as they did for women with genetic mutations that are known to significantly raise breast cancer risk.
- Up to a third of surgeons rarely referred patients for genetic counseling; many said they never delayed surgery so that genetic testing results could be available before making treatment decisions.
- 51% of women who were found to have a VUS in a gene that increased cancer risk or no mutation at all had bilateral mastectomies, treatment that is considered to be extreme and unnecessary for women who do not have known harmful mutations or other inherited factors that raise risk.
In breast cancer patients who have a BRCA mutation, bilateral mastectomy increases survival and reduces the risk of a second breast cancer. It does not, however, increase survival for women of average risk.
Clinical practice guidelines clearly state that variations of unspecified significance are mostly benign and should not be considered to confer high cancer risk. Patients with these variants should be considered at average risk for breast cancer and should be counseled similarly to patients whose genetic test is negative for a mutation. In other words, mastectomy is not recommended for these women. Yet this study shows that many patients don't understand the meaning of a VUS, while too many physicians mistakenly believe that a VUS means high cancer risk and they recommend mastectomy for VUS patients, just as they do for patients with mutations that are known to increase risk.
Genetic testing is a specialty; a specialty that is best provided by qualified genetic counselors.
Experts recommend always seeing a genetic counselor before and after testing.
If you’ve already been tested and notified that you have a VUS, consult with a genetic counselor, even (and especially) if a surgeon or other health care professional ordered the test (unless that professional is also certified as a genetic counselor). Even if your VUS results was given years ago, check with the laboratory that performed your test or a genetic counselor periodically to determine whether your VUS has been reclassified, which can occur as more information about a particular VUS becomes available. It may just save your breasts.
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