Physicians' Misunderstanding of Genetic Test Results May Hamper Mastectomy Decisions
A recent survey of over 2,000 women newly diagnosed with breast cancer found that half of those who undergo bilateral mastectomy after genetic testing don't actually have mutations known to confer increased risk of additional cancers, according to a study by researchers at the Stanford University School of Medicine and four other U.S. medical centers.
Instead the women had what are known as variants of uncertain significance, or VUS, that are often eventually found to be harmless. A bilateral mastectomy is a surgical procedure in which both of a woman's breasts are removed after a diagnosis of cancer in one breast.
The finding highlights the need for genetic counselors to help both patients and physicians better understand the results of genetic testing intended to determine a woman's risk for cancer recurrence or for developing a separate cancer in her ovaries or unaffected breast.
"Our findings suggest a limited understanding among physicians and patients of the meaning of genetic testing results," said Allison Kurian, MD, associate professor of medicine and of health research and policy at Stanford. "Clinical practice guidelines state that variants of uncertain significance should not be considered to confer high cancer risk, and that patients with these variants should be counseled similarly to a patient whose genetic test is normal. However, many of the physicians surveyed in our study stated that they manage these patients in the same way as they do patients with mutations known to increase a woman's risk."