ACMG the Latest to Come Out Against Genetic Testing for All Breast Cancer Patients

The debate over the need for genetic testing of all breast cancer patients for germline pathogenic or likely pathogenic variants in BRCA1, BRCA2 and other breast cancer-linked genes continues with the American College of Medical Genetics and Genomics (ACMG) declining to recommend general testing. However, the ACMG did recommend evaluating all breast cancer patients for their need for germline genetic testing to assess their inherited risk for the disease. Lack of Consensus on Need for Genetic Testing of Breast Cancer Patients Of all cancers that impact women in the U.S., breast cancer has the highest incidence, regardless of race or ethnicity with an estimated 271,270 new cases and 42,260 deaths in 2019. Despite the longstanding availability of testing for inherited cancer, including the BRCA1/2 genes for which testing has been clinically available for more than two decades, only a small proportion of the at-risk population has traditionally been tested. The ACMG statement, which the nationally recognized genetic medicine professional organization published in its official journal, Genetics in Medicine, on Dec. 13 is contrary to a consensus guideline issued by the American Society of Breast Surgeons in February 2019 which does recommend genetic testing for BRCA1/2 and PALB2, and where clinical factors and family history dictate, for other genes. However, the ACMG statement is consistent with the recently updated National Comprehensive Cancer Network (NCCN) guidelines recommending the use of patients’ own cancer history and family history to determine the appropriateness of genetic testing assessing the risk of breast, ovarian and pancreatic cancers. For the details, see Diagnostic Tests & Emerging Technologies (DTET) Jan. 2, 2020. There is insufficient evidence to recommend universal genetic testing for BRCA1/2 alone or in combination with multi-gene panels for all breast cancer patients, notes the lead author of the ACMG statement, Tuya Pal of Vanderbilt University Medical Center. What the ACMG Did Recommend While not coming out for universal testing, the ACMG made a point to emphasize that it “considers germline genetic information to be critical to the management of patients with genetic conditions.” Accordingly, it did recommend that all women with breast cancer be evaluated for the need for genetic testing based on existing clinical criteria, including:

• Age at diagnosis;
• Family cancer history;
• Expression of estrogen progesterone receptors; and
• HER2 expression.

The ACMG noted that such testing is not being provided, citing estimates that less than 10 percent of adults with BRCA1/2 pathogenic or likely pathogenic variants in the US have been identified, and less than 20 percent of breast and ovarian cancer patients who should receive testing according to guidelines are actually receiving it. Furthermore, the ACMG recommends that clinicians:

• In discussions with patients, be aware of the current insufficient evidence to support genetic testing for all patients with breast cancer;
• After identifying a pathogenic or likely pathogenic mutation in moderately penetrant breast cancer genes, recognize that guidance is based on consensus recommendations and that enhanced screening, to date, has not been associated with enhanced survival or earlier stage diagnosis;
• Whenever genetic testing is performed on a clinical basis, ensure it includes full gene sequencing and is conducted in a CLIA-certified or CAP-accredited laboratory.

Takeaway  Skepticism clearly remains on the clinical utility and cost-effectiveness of genetic testing for all breast cancer patients. The ACMG urged professional societies to work together to advance harmonized, evidence-based recommendations and reduce barriers to care. “Testing alone will not improve outcomes but rather implementation of appropriate care following testing is required,” the organization wrote.