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.