Genetic Testing Underutilized in Early Breast Cancer – MedPage Today

Posted: July 12, 2017 at 11:52 am

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Patients with early-stage breast cancer often undergo definitive surgery without genetic testing, or before BRCA1/2 testing has been performed, and the results frequently aren't explained to them, a survey of surgeons and patients found.

Approximately one-third of surgeons said they rarely referred patients for genetic counseling, and only 73% of high-volume surgeons and 35% of lower-volume surgeons said they were confident in discussing genetic test results with their patients, reported Allison Kurian, MD, of the Stanford University School of Medicine in California, and colleagues.

And 27% of patients who turned out to have high-risk variants of the BRCA1/2 genes, and one-third of patients at average risk, weren't tested until after surgery. In fact, 17% of high-volume surgeons and 38% of lower-volume surgeons said that they never delayed surgery for genetic test results, Kurian's group wrote in the Journal of Clinical Oncology.

Furthermore, half of lower-volume surgeons and one-quarter of high-volume surgeons said they managed patients with known high-risk mutations of BRCA1/2 the same way as they managed patients with genetic variants that were of uncertain significance, which often turn out to be benign, Kurian and colleagues said.

"This study offers a unique window into a transformative period for precision medicine and the challenge of implementing advances in genomic technology into breast cancer treatment," Kurian and colleagues wrote. "Effective genetic testing requires clinicians to assess pretest risk, counsel patients on testing implications, order an appropriate test, communicate results, and develop an appropriate management plan.

"Furthermore, there is urgency for a patient with newly diagnosed breast cancer; genetic tests are often desired to inform surgical decision making, yet patients may fear that the 3-week testing process will dangerously postpone treatment," they noted. "Although some patients may prefer to defer testing until after the hectic period of initial decision making, for others, this delay may represent suboptimal care. In addition, it is concerning that a substantial proportion of surgeons, particularly those who saw the fewest patients with breast cancer, never postponed surgery until test results were available."

In an accompanying editorial, Soojin Ahn, MD, and Elisa Port, MD, both breast cancer surgeons at Mt. Sinai Hospital in New York City, echoed the study authors' concerns. "Although many patients with newly diagnosed breast cancer are eager to undergo surgery as soon as possible, the physician should explain and advise about the benefits of waiting for the genetic test results in certain situations ... " they said. "Also important is that patients are reassured that a delay of surgery for a few weeks will in no way affect survival or risk of recurrence.

"Even more alarming was the number of surgeons who admitted to managing patients with a variant of uncertain significance (VUS) the same way as BRCA mutation carriers, which likely led to 51% of average-risk patients with a VUS who underwent bilateral mastectomy," they said. "Because most VUSs are ultimately reclassified as benign, the management of an individual who carries a VUS should be based on personal and family history and not on the presence or absence of the variant itself.

"Our job as breast surgeons is to provide appropriate and accurate information in concert with our genetic counselors to convey that more-extensive surgery is no better than lumpectomy with respect to overall breast cancer survival and systemic recurrence and that a VUS has the potential to be reclassified as benign. Then it is our patients' decision," Ahn and Port advised.

Kurian and colleagues surveyed 2,502 women diagnosed with stage 0-II breast cancer in 2014-2015. These women were part of the Surveillance, Epidemiology, and End Results (SEER) program registries of the state of Georgia and Los Angeles County. Surveys were mailed approximately 2 months after the women underwent surgery. Most women (98%) reported their surgeon's name, and these doctors were surveyed as well. Surgeons were classified as high-volume if they treated more than 50 patients with breast cancer in the past year.

More than half of women surveyed (1,535, or 61%) reported no genetic testing and were excluded. Approximately 300 women were excluded for other reasons, leaving a final sample of 666 women who underwent genetic testing. Of these, 72% said no mutation was found, 9% said a variation of uncertain significance was found, and 7% reported a high-risk mutation in BRCA1/2 or other risk-associated gene.

Of note, the study found that type of insurance was a factor associated with delay of genetic testing. Compared to patients with private insurance, patients were more likely to be tested after their surgery if they had Medicare (OR 2.6; 95% CI 1.6-4.2), Medicaid (OR 2.3; 95% CI 1.1-4.5), or no insurance (OR 2.5; 95% CI 1.5-4.3).

Limitations of the study included its reliance on patient self-reports, which can be inaccurate, and the potential for selection bias, Kurian and colleagues noted. However, their analysis was weighted for survey non-response to address this bias, they said.

"Our findings reinforce the need to address challenges in personalized communication about genetic testing," Kurian's group concluded. "Clinicians' skill in communicating about precision medicine technologies will determine whether these advances translate into better care and outcomes."

Ahn and Port added that, "Genetic testing represents one of the most significant advances in personalizing breast cancer treatment and individualizing care. Optimization of testing implementation and accurate interpretation should be paramount to the surgeon who cares for women with breast cancer. As Kurian et al. demonstrate, on this front, there is much room for improvement."

The study was funded by the National Cancer Institute.

Kurian reported research funding from Invitae, Myriad Genetics, Ambry Genetics, GenDx, and Genomic Health.

Ahn and Port reported no financial relationships.


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Genetic Testing Underutilized in Early Breast Cancer - MedPage Today

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