A NEW GUIDELINE released by the American Society of Clinical Oncology (ASCO) and the Society of Surgical Oncology (SSO) recommends that all women diagnosed with breast cancer who are 65 years old or younger should be offered germline genetic testing for BRCA1 and BRCA2 mutations.

The new guideline, published in the February 2024 issue of Journal of Clinical Oncology, seeks to clear up previous uncertainties about germline testing and may help identify more patients who could benefit from treatments like PARP inhibitors, targeted drugs that can be used when a patient has a BRCA1 or BRCA2 mutation.

Germline genetic testing looks at a patient’s DNA for mutations inherited from their parents. BRCA1 and BRCA2 genes produce proteins that help repair damaged DNA, but mutations in the genes can significantly increase a woman’s risk of developing cancer, mainly breast or ovarian cancer, and of developing those cancers at a young age.

Finding these mutations could change the course of treatment recommended for a breast cancer patient, but before the new guideline was issued, testing was limited to patients who have a strong family history of cancer or other apparent risk factors.

“The field of germline testing has changed markedly in the last decade,” Isabelle Bedrosian, a breast surgical oncologist at the University of Texas MD Anderson Cancer Center in Houston and one of the guideline authors, says. Bedrosian notes that the availability of panel tests looking into mutations in multiple genes associated with breast cancer has made it more complicated for providers to decide who should be referred for testing and for what tests.

“The goal for these new guidelines, therefore, was to provide a simplified framework for providers as to how they should approach the issue,” she says. “What factors should be considered in ordering a test? Who should be tested? What should the scope of testing look like?”

In addition to testing all patients 65 and under, the recommendations also call for germline testing in newly diagnosed patients who are older than 65 if they are candidates for treatment with a PARP inhibitor, were diagnosed with triple-negative breast cancer, have a personal or family history that suggests a mutation may be present, were assigned male sex at birth, or are members of a population known to have an increased risk of certain mutations, such as those with Ashkenazi Jewish ancestry.

Patients who are undergoing BRCA1 or BRCA2 testing should also be offered additional panel testing for other genes that may predispose them or their family members to cancer based on personal and family history, the new guideline says.

“We’ll test a panel of different things for the patient,” Tiffany Onger, a medical oncologist at Cleveland Clinic, explains. “The specific panel is based on the person’s specific family history.”

Onger stresses how important it is for patients to be as detailed as possible about any sort of cancer that family members have had in the past to provide an accurate picture for doctors to recommend appropriate panel testing.

“A lot of patients don’t know that mutations and a gene that’s associated with breast cancer can also be associated with other cancer types,” she adds.

While the new guideline offers clear direction on who should get germline genetic testing and when they should be tested, Onger says it may take a while for the recommendations to be widely implemented. Current and former patients should feel empowered to ask about genetic testing now if they believe they fall into any of the categories specified in the guideline for testing, she says.

“I love to empower patients to be more aware. For patients who weren’t tested before and no longer have active disease, I would still encourage them to ask about it,” Onger says. “Germline genes don’t change over time. I want people to know it’s not too late to test.”

Though not specifically mentioned in the new guideline, an important caveat is that using direct-to-consumer genetic testing companies like 23andMe is generally not recommended by medical professionals.

“Direct-to-consumer genetic testing platforms are quite variable and may not always provide valid results and sufficient counseling to guide follow-up care,” Bedrosian explains. She says that patients who have gotten results from at-home tests should speak to a genetic counselor or health care provider experienced in cancer genetics about their test results.

Laura Gesualdi-Gilmore is a Chicago-based freelance journalist who covers topics ranging from health and wellness to luxury travel.