A new study shows limited use of genetic counselors and half of women at average risk with genetic variants of uncertain significance (VUS) underwent bilateral mastectomy. The results highlight physicians’ knowledge limits in interpreting breast cancer genetic testing, the study published in the Journal of Clinical Oncology has shown.1 

“We’re learning that clinicians’ knowledge of breast cancer genetics can be highly variable. It’s important for women at high risk of carrying a dangerous mutation to see someone with expertise in cancer genetics when planning their care. Unfortunately, in many cases, genetic counselors may not be optimally integrated into the care of newly diagnosed cancer patients, making it difficult to rapidly triage these patients.,” Allison Kurian, MD, of Stanford University School of Medicine, said in a news report.2

According to the study findings, despite an increasing use of genetic testing in patients with breast cancer, little is known about its impact on treatment. Dr Kurian and colleagues surveyed patients with breast cancer diagnosed in 2014 to 2015 and their surgeons to assess the impact of genetic testing on bilateral mastectomy use. 

In total, the study included 666 patients who underwent genetic testing associated with their breast cancer diagnosis. Patients without private insurance reported more delays associated with genetic testing prior to surgery. Involvement of a genetic counselor was reported in approximately half of the participants.

A mutation in BRCA1/2 was associated with a higher rate of bilateral mastectomy (80% in high risk, 85% in average risk). However, patients with genetic VUS commonly underwent bilateral mastectomy (43% in high risk, 51% in average risk).

A higher volume of patients with breast cancer was tied to an increased confidence in discussing genetic testing by surgeons. But many of the surgeons reported treating patients with BRCA1/2 and VUS similarly.1

“Our study highlights the urgent need for improved patient access to cancer genetics experts, particularly genetic counselors, and for educating physicians about the appropriate use of genetic testing and interpretation of test results, Dr Kurian continued in the statement.2