A Geneticist and PCP Detail Considerations With New Screening Recommendations for Breast Cancer

Although the new United States Preventive Services Task Force (USPSTF) guidelines shed light on best practices for females at average risk of developing breast cancer, several questions remain especially for those with dense breasts. The USPSTF recommendations released in April 2024 are an update to the prior guidelines from 2016, and state that there is a moderate net benefit to biennial screening for all females, age 40-74, with an average risk of breast cancer (Grade B recommendation). In 2016, the USPSTF recommended biennial screening mammogram for females aged 50-74 (Grade B), however, screening was also an option for those 40-49 (Grade C).¹

We spoke with primary care physician (PCP) Lydia Pace, MD, MPH; and Brittany Bychkovsky, MD, MSc, to discuss current breast cancer screening guidance and factors that influence risk.

Pace emphasized the importance of an individualized approach to breast cancer screening.

“In my practice, I try to take an individualized approach—sometimes I do annual mammography screening for women who have extremely dense breasts. [In certain instances] for women under 50 years old who have other risk factors such as atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ and high breast density, we’ll recommend supplemental MRI if they’re comfortable with it,” Pace said in an interview with OncLive®. “But we always need to counsel women on the downsides of supplemental imaging [as] adding supplemental breast ultrasound or MRI dramatically increases the risk of a false positive findings.”

She added, “when breast MRI or ultrasounds are performed in addition to mammogram, there are more callbacks for additional imaging and sometimes [more] biopsies are performed that don’t lead to a cancer diagnosis and very likely lead to more overdiagnoses. Supplemental imaging carries harm and it is important that patients know that it carries harm without a clear understanding of benefit at this point.”

The USPSTF wrote in their final recommendation statement that more research is needed to determine if supplemental screening with breast MRI or ultrasound has a benefit on improving breast cancer outcomes in those with dense breasts.1 Currently, only 10% of females have extremely dense breast tissue, however, up to 50% have heterogeneous or extremely dense breast tissue. Bychkovsky noted that most states have laws in place that require females to be informed if they have dense breast tissue.

Bychkovsky also explained that efforts are also underway to enhance access to breast cancer screening so that patients do not incur financial toxicity when undergoing diagnostic breast imaging with mammogram, ultrasound, and MRI. In Massachusetts, Bychkovsky and colleagues have advocated for Bill H.4410: An Act Relative to Breast Cancer Equity and Early Detection. Bill H.4410 has received a favorable review by the Massachusetts Senate Health Care Financing Committee and was referred to the committee on House Ways and Means in April 2024.²

In an interview with OncLive, Pace and Bychkovsky explained approaches to screening and detailed considerations with the final screening recommendations. Bychkovsky is an assistant professor of medicine at Harvard Medical School and senior physician at Dana-Farber Cancer Institute and Pace is an associate physician in the Divisions of Women’s Health and General Internal Medicine at Brigham and Women’s Hospital and an associate professor of medicine at Harvard Medical School.

OncLive: How has the referral process for genetic testing evolved?

Bychkovsky: In the past, we emphasized a family history of breast cancer and/or personal factors such as a diagnosis of triple-negative breast cancer at a young age, diagnosis of breast cancer before the age of 45, and certain ancestries [as notable]. In January 2024, new guidelines came out from ASCO and the American Society of Surgical Oncology emphasizing that all patients with a breast cancer diagnosis and any breast cancer survivors are candidates for genetic testing.

We have migrated from very prescriptive recommendations to testing patients more broadly who have a breast cancer diagnosis. Not only are we testing more patients with breast cancer, but we’re also testing more patients with pancreatic cancer, prostate cancer, and a sarcoma diagnosis. The trend that’s happening in cancer genetics is that we’re offering testing for more individuals with a cancer diagnosis and then if they’re identified to have a cancer susceptibility gene, we are doing cascade testing and targeting their biologic family members for testing when age appropriate.

What is key to know about the recent USPSTF breast cancer screening recommendations?

Pace: The USPSTF recommended screening everyone at the age of 40, I believe, in the hope that it would help mitigate some of the mortality difference between Black women and White women in the US, since Black women experience 40% higher breast cancer mortality than White women. Research will be really important to examine the impact of this guideline change on uptake of mammography, follow-up of abnormal mammograms, and diagnostic evaluation of women with breast concerns. In some facilities, there may be concern that increasing demand for mammography among lower-risk women—for example, women in their 40s without breast cancer risk factors—may decrease access for higher-risk women. And I believe it’s important to emphasize that the high breast cancer mortality rates among Black women are largely attributed to the effects of structural racism leading to delays in diagnosis, inferior treatment quality, and more aggressive tumor types. Addressing these issues is essential.

Although some of the literature [in 2016] had been moving more towards a risk-based approach to screening mammography—trying to do more risk stratification of women upfront and recommending some women start [screening] at 50 years old and some women start at 40 years old—these [2024] recommendations try to give everyone a one size fits all approach starting at 40 years old. The new USPSTF mammography screening guidelines do not address referrals for genetic testing and don’t address screening strategies for people who are at higher genetic risk.

The USPSTF has a recommendation on ‘BRCA-Related Cancer: Risk Assessment, Genetic Counseling, and Genetic Testing’ which was last updated in 2019. It appears [as if] it’s being updated now—they’re probably doing evidence review now and will release updated guidelines at some point.

How do you approach breast cancer screening for women with dense breasts?

Pace: For women with dense breasts, the data that exist are fairly limited in terms of the benefit of supplemental screening. Of the existing data, none suggest that supplemental screening for women with dense breasts reduces important breast cancer outcomes, including likelihood of dying from breast cancer. Therefore, the USPSTF concluded that there was not enough evidence to recommend supplemental screening for women with dense breasts which puts both clinicians and patients in a tricky situation especially with mandated reporting of breast density. There remains a lot of uncertainty about what to recommend for women in this situation.

Bychkovsky: A lot of the breast density laws that were put in place across the country [occurred] during a time where we were primarily doing 2D mammograms and now we’re doing 3D mammograms. Density matters on 3D, however, the sensitivity of 3D tomography is much greater than 2D. [Of the] 4 density levels—fatty, scattered, heterogeneous density, and extremely dense breast tissue—only approximately 10% of patients have extremely dense breast tissue. That’s the category that providers pay most attention to even though patients with heterogeneous density and extremely dense [breasts] are notified that they have dense breasts.

Density is also not static—it changes with age. I’ll often see patients who think that they have dense breasts because they may have been told that years ago, but [at the time that] I see them, they] no longer do on imaging.

Pace: I think about density in light of the rest of a patient’s risk factors, and some of our risk calculators allow us to incorporate patient risk factors such as age and family history, along with breast density. You have to think about density where it fits in with the rest of a patient’s risk profile.

How do you approach breast cancer screening for women over the age of 75?

Pace: Overall, we have limited data on women who are 75 years of age or older because they weren’t included in the randomized trials of mammography screening. Most clinicians I know tend to take an individualized approach to screening in older women that takes their comorbidities and life expectancy into account. The American Cancer Society has previously recommended that we [shouldn’t] screen if we think that a patient’s life expectancy is 10 years or less, and many clinicians I know use that approach.

Unfortunately, there is not great data in this population. But overall, the likelihood of deriving benefit decreases as women age above 75 years old and the likelihood of increasing harm increases as well. We do recommend a tailored and individualized approach for older women.

References

Nicholson WK, Silverstein M, Wong JB, 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

An act relative to breast cancer equity and early detection. The 193rd General Court of the Commonwealth of Massachusetts. Updated April 18, 2024. Accessed May 29, 2024. https://malegislature.gov/Bills/193/H4410