Biennial Mammography Starting at Age 40 Proves Effective in Breast Cancer Screening Strategies

Breast cancer remains a significant public health challenge, with screening strategies continuously evolving to improve early detection and patient outcomes. In a recent collaborative modeling study conducted for the US Preventive Services Task Force, researchers aimed to evaluate the outcomes of various mammography screening strategies to inform US breast cancer screening guidelines.

The study, conducted by a team of experts including Amy Trentham-Dietz, PhD, MS, and colleagues, utilized six Cancer Intervention and Surveillance Modeling Network (CISNET) models to compare screening outcomes derived from national breast cancer incidence data, screening performance, treatment effects, and mortality. The research focused on 36 different screening strategies that varied in start and stop ages (40, 45, 50, 74, 79 years), intervals (annual, biennial, hybrid), and techniques (digital mammography or digital breast tomosynthesis [DBT]).

Key findings include that biennial screening with DBT, starting at ages 40, 45, or 50 until age 74, significantly reduced breast cancer mortality compared to no screening — with a median of 8.2, 7.5, or 6.7 breast cancer deaths averted per 1000 women screened, respectively. This equates to a 30% reduction in breast cancer mortality with 1376 false-positive recalls and 14 cases of overdiagnosis per 1000 women screened. Furthermore, the benefit-to-harm ratios for continuing screening until age 79 were comparable or superior to stopping at 74 years.

The study particularly noted that annual screening strategies lead to higher mortality reductions but also more false-positives and overdiagnoses. Moreover, Black women were highlighted as a group that could see a significant decrease in breast cancer mortality disparities when adopting annual screenings from age 40 to 49 years followed by biennial screenings.

Overall, the collaborative effort suggests that biennial mammography, starting at age 40, is effective in reducing breast cancer mortality and increasing life-years gained per mammogram screened. Tailoring more intensive screenings for higher-risk groups can maintain comparable benefit-to-harm balances and help mitigate mortality disparities.

Conducted by leading researchers across the United States and published online on April 30, 2024, in JAMA, this study solidifies the importance of personalized, risk-based breast cancer screening strategies.

For further details and comprehensive insights, please refer to the full article: JAMA. doi:10.1001/jama.2023.24766.

Acknowledgments to the dedicated researchers involved in this important work, and to built with the help of Buoy Health.

(Reprinted) E1 E14 JAMA Published online April 30, 2024