21 February, 2019

ASBrS Calls for Genetic Testing for All Breast Cancer Patients

The American Society of Breast Surgeons (ASBrS) is calling for all patients with breast cancer to be offered genetic testing and to not restrict such tests only to patients at highest risk for genetic mutations, as currently recommended by the National Comprehensive Cancer Network (NCCN).

The call for universal genetic testing for all patients with breast cancer was made in a new ASBrS position statementand accompanying documents published online on February 14.

“The rationale behind universal genetic testing is that certain mutations will affect treatment,” Walton Taylor, MD, ASBrS president, told Medscape Medical News.

These mutations “can affect when patients get radiation therapy, what chemotherapy they may get, and even what surgery they may get,” he continued, “so genetic testing is huge for what you are going to do to manage the cancer, and not only how you are going to manage the cancer, but also surveillance for future cancers, both breast and nonbreast.”

“And all this plays a huge role in patients’ lives, too, not only in the management of what patients have now but what they could get in the future,” he emphasized.

Beyond the NCCN Guidelines

The NCCN guidelines were originally established to help identify patients who were most likely to carry a mutation in the BRCA1 or BRCA2 genes, both of which produce tumor-suppressing proteins, thereby increasing breast and, usually, ovarian cancer risk.

Current NCCN guidelines also recommend testing family members of patients with established pathogenic variants, but in so doing only identify about half of individuals carrying the same variants.

Impetus to develop the new ASBrS consensus guidelines was precipitated by a recent study that found almost half of patients with breast cancer who harbored either a pathogenic or a likely pathogenic variant for breast cancer on multigene panel testing did not meet current NCCN guidelines for genetic testing.

Five Key Recommendations

The new ASBrS consensus statement contains five key recommendations, summarized as follows.

  • All knowledgable professionals may be involved in the education and counseling of patients about genetic testing and recommend testing to them. However, professionals need to be mindful that there is no consensus about which genes should be tested in a given clinical scenario, which multigene panel is best to order, and what to do when a given mutation is detected. Referral to a genetic counselor may help resolve what appears to be considerable uncertainty about genetic testing for breast cancer patients overall.
  • All patients with breast cancer should undergo genetic testing. Patients with newly diagnosed breast cancer or those with a personal history of breast cancer should receive genetic testing and the multigene panel should include at minimum the BRCA1 and BRCA2 genes as well as the PALB2 gene. Surgeons need to be mindful that identification of any mutation may affect local treatment as well as the type of systemic therapy offered following surgery. Family members may also be offered genetic testing and, if a mutation is identified, they may be counseled on risk reduction strategies that could help prevent the development of future cancers.
  • Patients who have already undergone genetic testing may still benefit from newer, greatly expanded genetic tests. Patients who underwent genetic testing prior to 2014 would not have been tested for the PALB2gene or other potentially relevant mutations, nor may they have been tested for large genomic rearrangements in BRCA1 or BRCA2 genes. So anyone who has tested negative for pathogenic variants in the past should be considered for updated testing.
  • Patients who do not have a history of breast cancer but who meet current NCCN guidelines should undergo genetic testing. Testing an affected relative first is more informative than testing unaffected patients but if not feasible, then testing an unaffected family member should be considered, provided patients are interested in knowing the results.
  • Patients need to understand that if they test for a variant of uncertain significance, no clinical action will be taken. Detection of a variant of uncertain significance does not influence the management of breast cancer so patients should be prepared to live with this ambiguity.