Enhancing the Referral Process for Genetic Testing Represents Key Next Step in Breast Cancer

As recent guideline updates contribute to the further elucidation of the logistics of screening, the role of genetic testing continues to be parsed out, with Brittany Bychkovsky, MD, MSc, noting that findings ways to identify women at high-risk of developing breast cancer is crucial.

“For providers, there’s a need within every health care system to develop a system to identify patients who are at high risk for [developing breast cancer]; we should not be relying on a primary care doctor, surgeon, or an oncologist to recognize that a patient is high risk and refer them to genetics. There needs to be a way from a systematic perspective to identify these patients, counsel them appropriately that they are going to be referred for genetic testing, and have the referrals placed,” Bychkovsky, an assistant professor of medicine at Harvard Medical School and senior physician at Dana-Farber Cancer Institute, in Boston, Massachusetts, said.

Guidelines published by ASCO and the Society of Surgical Oncology (SSO) in January 2024 noted that testing for breast cancer susceptibility genes beyond BRCA1/2 should be offered to those with newly diagnosed breast cancer and breast cancer survivors as it informs medical therapy, influences surgical decision making, refines risk estimates of second primary cancers, and affects the care of family members.¹

ASCO and SSO also provided several recommendations regarding BRCA1/2 testing noting that they now recommend testing for all patients with recurrent breast cancer who are candidates for PARP inhibitors regardless of family history; who develop a second primary cancer in the ipsilateral or contralateral breast; and those with newly diagnosed breast cancer aged 65 years or younger and select patients over the age of 65 based on personal history, family history, ancestry, or eligibility for PARP inhibitors. Additionally, for patients with a prior history of breast cancer and without active disease, testing should be offered to those aged 65 years or younger when diagnosed and selectively in patients diagnosed after 65 years if it informs personal and/or family risk.

In an interview with OncLive^®, Bychkovsky and Lydia Pace, MD, MPH, a primary care physician (PCP) and associate physician in the Divisions of Women’s Health and General Internal Medicine at Brigham and Women’s Hospital, in Boston Massachusetts, as well as an associate professor of Medicine at Harvard Medical School, explained approaches to genetic testing for breast cancer. In an additional article, Pace and Bychkovsky highlighted approaches to screening and detailed considerations with the final United States Preventive Services Task Force (USPSTF) screening recommendations published in April 2024; this is an update to the previous 2016 guidelines.²

OncLive: How do you use breast cancer risk status to identify individuals for genetic testing?

Bychkovsky: The average lifetime risk of [developing] breast cancer in the general population is approximately 12% to 13%. If a patient has a greater than 20% lifetime risk, they’re considered high risk, but not everyone is managed the same [as] patients with a BRCA mutation or a TP53 mutation who have a greater than 60% lifetime risk of [developing] breast cancer. The moderate-risk genes include ATM, CHEK2, RAD51C, and RAD51D.

It’s important to identify patients who are at a high risk for breast cancer between the ages of 25 and 35. That’s the target age where if someone is perceived to be at a high risk, we would want them to be referred for genetic testing. I don’t want patients to have an extensive family history of breast cancer and be referred for the first time later in life–when this happens, it reflects as shortcoming of our systems and tells me that we are not performing risk assessments in a timely way.

How do you approach genetic testing as a PCP?

Pace: We PCPs try to use guidelines and the USPSTF is often our go-to, [but] sometimes guidelines are discordant and that can be tricky for us. We usually refer [patients for testing] so we’re typically not testing ourselves which is another frontier. Should we be testing more to increase access to patients? What benefits or challenges would that have? That’s a whole other health services area.

Right now, at my practice, we are incredibly fortunate to be able to refer to Dr Bychkovsky’s group which provides our patients with high-quality counseling—pretest counseling, posttest counseling, and clear guidance on how to manage results. Not every primary care clinician has that [type of] access for their patients and that’s another area where the US and the world have to move forward in order to realize the benefit of precision medicine and figure out how we get patients who receive care elsewhere the same quality of care.

When a patient is referred to you by Dr Pace, what are your first steps in terms of genetic profiling?

Bychkovsky: What typically happens is a patient is sent a series of questions about their personal and family history of cancer, and then they meet with a genetic counselor who confirms that history and builds a pedigree. We also ask questions about their current age, how many pregnancies have they had, how many children have they had, and any personal risk factors in regard to breast density on imaging.

We ask questions about alcohol use, exercise level, diet, [and other] lifestyle factors. The lifestyle factors are more part of the breast cancer risk assessment [and] that’s not considered as criteria to have genetic testing.

For genetic testing, we emphasize the family pedigree. On the family pedigree there’s a few things that stand out for me: any pre-menopausal breast cancer diagnoses in paternal relatives, pre-menopausal breast cancer diagnosis in first degree relatives on the maternal side, cancer diagnoses that are at younger ages are significant, [and] ovarian or pancreatic cancer diagnoses. Those types of [factors] allow patients to be eligible for cancer genetic testing. Every case is a bit different, but I’m emphasizing the pedigrees that we would see for a patient who has a risk for a hereditary breast cancer gene.

If there’s a family history of colorectal, endometrial, or ovarian cancer, that’s a scenario where we would want to do genetic testing for Lynch syndrome. We tend to do broad panel testing with 40 to over 100 genes and that is a current standard and has shifted through the years. Prior to 2013 when patients had genetic testing, they were primarily having genetic testing for BRCA1/2, but now we’re doing large gene panels.

At Dana-Farber, we started [having] anyone with a cancer diagnosis meet with a genetic counselor only to have genetic testing. This has enhanced access to cancer genetic testing, as opposed to meeting with both a genetic counselor and a physician, such as a medical oncologist or a geneticist. That is something within cancer institutions that needs to be explored because if a patient has a preexisting cancer diagnosis, they already have a medical oncologist who has a lot of background and training in cancer genetics, and there’s not a need for them to see another geneticist or another physician for genetic testing. There needs to be some thoughtfulness about how we can build systems within whatever network providers are working in to enhance access to cancer genetic testing.

References

1. Bedrosian I, Somerfield MR, Achatz MA, et al. Germline testing in patients with breast cancer: ASCO–Society of Surgical Oncology guideline. J Clin Oncol. 2024;42(5):584-604. doi:10.1200/JCO.23.02225
2. US Preventive Services Task Force, Nicholson WK, Silverstein M, et al. Screening for breast cancer: US Preventive Services Task Force recommendation statement. JAMA. Published online April 30, 2024. doi:10.1001/jama.2024.5534