Study identifies need for surgeons to maximize benefits of genetic testing for surgical decisions in breast cancer.
According to a new study published in the Journal of Clinical Oncology (JCO), nearly 50% of newly diagnosed patients with breast cancer undergo a bilateral mastectomy (BLM) even though they have mutations in the BRCA1/2 genes that are classified as variants of uncertain significance (VUS).
Several of the researchers who are a part of the JCO study published a paper in JAMA earlier this year, which found that women with breast cancer would generally like to receive genetic testing and counseling, but less than one-third actually receive it. Of the 2529 women who had undergone surgery for breast cancer, only 29% reported that they had actually been tested.
For the current study, the authors surveyed a population-based sample of patients with breast cancer from 2 SEER registries in Georgia and Los Angeles, who were diagnosed between 2014 and 2015. About 68% (n = 2497) of the 3672 patients responded to questions on their genetic testing experience; the patients’ attending surgeons were also surveyed on genetic testing and results management.
Of the patients who responded to questions on genetic testing, only about 27% (n = 666) reported genetic testing. Nearly two-thirds of patients were tested prior to surgical treatment, and patients enrolled in commercial health plans did not face as much delays as those on government health plans. While 50% of patients discussed their results with a genetic counselor (57% at higher pretest risk and 42% at average risk), there was a pattern of discrepancy when it came to BLM in patients with VUS versus pathogenic mutations in the BRCA1/2 genes. While 80% of higher risk patients with pathogenic mutations in BRCA1/2 underwent BLM, 43% of higher risk patients with VUS also underwent BLM.
Interestingly, many women undergo BLM prior to receiving genetic testing or even seeing their results, according to the study.
The authors write that while a surgeon’s confidence with discussing genetic testing with patients increased with the volume of patients being managed, many surgeons continued to manage patients with VUS and with pathogenic mutations in BRCA1/2 the same way.
“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 Medicine. She noted that patients with VUS should not be considered at high risk for developing breast cancer, unlike what several surgeons in their study did.
Senior author on the study, Steven Katz, MD, MPH, professor of medicine and of health management and policy at the University of Michigan, believes there’s need to maximize the benefits of genetic testing for patients with breast cancer, “to incorporate results into treatment decisions.”