Risk-Based Breast Cancer Screening Outperforms Annual Mammograms, Study Finds

A recent study suggests that customizing breast cancer screening based on a woman's individual risk may be more effective than standard annual mammograms.

The research, published in the Journal of the American Medical Association (JAMA) on Friday, indicated that women undergoing risk-based screening were more likely to have breast cancers detected at an earlier and more treatable stage compared to those receiving annual mammograms regardless of their personal risk factors.

Dr. Laura Esserman, who is the director of the University of California-San Francisco Breast Care Center, stated in a news release that the study's findings should revolutionize clinical guidelines for breast cancer screening and transform clinical practice.

The study involved over 14,000 women who underwent breast cancer screening tailored to their individual risk. These risk assessments considered factors such as age, genetics, lifestyle, health history, and breast density. The women were divided into risk categories, resulting in these screening recommendations:

• % were in the lowest risk category and generally advised to delay screening until age 50.
• % were at average risk and advised to undergo screening every two years.
• % were at elevated risk and advised to undergo annual screening.
• % were at highest risk and advised to undergo two screenings per year, alternating between mammograms and MRI scans.

According to Dr. Esserman, this personalized approach starts with evaluating risk by looking at genetic, biological, and lifestyle elements. This evaluation can then inform effective prevention strategies.

The researchers compared the outcomes of these women with those of another group of over 14,000 women who received annual mammograms. Participants were enrolled in the study between September 2016 and February 2023, with follow-up extending through September 2025.

The study found that fewer women in the risk-based screening group were diagnosed with advanced cancers (stage IIB or higher). The risk-based screening group had approximately 30 cases of advanced cancer per 100,000 person-years, compared to 48 cases per 100,000 person-years in the standard mammogram group. Person-years represent the cumulative amount of time each person spent in the study.

Researchers also noted that risk-based screening could reveal potential risks that a woman might not be aware of. For instance, 30% of women who tested positive for genetic markers increasing their breast cancer risk did not report a family history of the disease. These women would typically not be offered genetic testing under current guidelines.

Dr. Allison Fiscalini, director of the Athena Breast Health Network at UCSF, explained that this study is among the first to offer genetic testing to all women, irrespective of family history. She added that when used as part of a thorough risk assessment, the results could significantly improve the safety and effectiveness of both screening and prevention.

Currently, researchers are actively recruiting participants for a follow-up clinical trial. The goal of this trial is to improve the identification of women at higher risk for more aggressive forms of breast cancer.

In response to the study's findings, the American College of Radiology (ACR) stated that the research does not provide sufficient evidence to justify changes to current breast cancer screening guidelines. The ACR pointed out that many women did not adhere to their recommended screening schedules. They also noted that the study did not identify a large enough number of cancers to produce optimal statistical analysis. The ACR stated that the number of cancers found was small and likely not representative of the population, also noting that the highest risk group contained fewer than 300 patients.

The U.S. Centers for Disease Control and Prevention (CDC) offers additional information on breast cancer screening.