Five-Year Absolute Risk-Based and Age-Based Breast Cancer Screening in the US.

Importance: General mammography screening guidelines target women at average risk within a specified age range (age based) and do not consider absolute risk of individual women at a given age (risk based). Objective: To compare outcomes of mammography screening strategies that vary by 5-year risk of invasive breast cancer vs age-based strategies. Design, Setting, and Participants: This decision analytical model used 2 established Cancer Intervention and Surveillance Modeling Network (CISNET) breast cancer models and simulated US women born in 1980 who were aged 40 years or older without a prior history of breast cancer. Modeling analyses were conducted from April 2023 to April 2025. Intervention: Digital breast tomosynthesis delivered via 50 screening strategies (3 age based and 47 risk based) vs a no-screening scenario. Five-year absolute invasive breast cancer risk was based on the validated Breast Cancer Surveillance Consortium, version 3 calculator. Women's 5-year breast cancer risk was categorized as low, average, intermediate, or high. Main Outcomes and Measures: Primary outcomes included lifetime number of breast cancer deaths averted and false-positive screening recalls. Lifetime outcomes were averaged across models and expressed per 1000 women screened. Results: Nine risk-based screening strategies were associated with a comparable or greater number of deaths averted than biennial age-based screening from ages 40 to 74 years (B40-74) (range across strategies for mean model estimates, 6.8-7.5 per 1000 women vs 6.8 per 1000 women) as well as reduced false-positive recalls by 8% to 23% (1050-1257 per 1000 women for risk-based screening strategies vs 1365 per 1000 women for B40-74). For example, a risk-based approach using a combination of biennial screening (for women at low risk aged 55-74 years, at average risk aged 50-59 years, at intermediate risk aged 45-54 years, and at high risk aged 40-49 years) and annual screening (for women at average risk aged 60-74 years, at intermediate risk aged 55-74 years, and at high risk aged 50-74 years) would be associated with 6% more breast cancer deaths averted than B40-74 (7.2 vs 6.8 per 1000 women) and 13% fewer false-positive recalls (1190 vs 1365 per 1000 women). Results were consistent across the 2 CISNET models, and the relative difference in breast cancer deaths averted between B40-74 and risk-based screening strategies was more pronounced than for life-years gained. Conclusions and Relevance: In this decision analytical modeling study of breast cancer screening, population risk-based screening using 5-year invasive breast cancer risk was associated with similar or greater benefits than age-based screening as well as reduced false-positive recalls. As personalized medicine advances, risk-based screening is poised to become a cornerstone of breast cancer prevention, offering a more nuanced and tailored approach to patient care.