Slovenian women's breast cancer risk assessment in the screening program

Abstract Background Nationally implemented breast cancer screening in Slovenia currently follows an age-based protocol, with a uniform approach for all women, despite differences in individual breast cancer risk. Evidence suggests that a risk-based strategy could reduce screening harms by tailoring interventions to personalized cancer risk. While personalized screening has professional and legal support in Slovenia, it is not organized at the population level. This study aimed to assess breast cancer risk distribution among Slovenian women and estimate the number of screening mammographies under risk-based protocols. Methods We performed a cross-sectional study of 11,898 women aged 50, invited to national screening and without prior breast cancer diagnosis. Data on risk factors, family history, and mammographic density were collected, and individual risks were assessed using the S-IBIS tool (IBIS risk calculator, tailored to Slovenian breast cancer epidemiology). Women were categorized into 10-year and lifetime risk groups. Also, we assessed adjusted risk at age 40 and simulated mammography numbers under different screening scenarios. Results Of the women invited, 57.0% completed questionnaires, with most categorized at average risk. Risk stratification showed 32.9% of participants with low, 62.8% population, 3.7% moderately increased, and 0.6% high 10-year breast cancer risk. Simulations suggested that personalized screening from age 40 to 74 could reduce mammography numbers in Slovenia by about one-third compared to the current age-based approach. Conclusions Risk assessment within routine breast cancer screening invitations in Slovenia is feasible. Personalized screening could decrease unnecessary mammographies and better align screening intensity with individual risk. These results provide a foundation for piloting and evaluating the introduction of risk-based breast cancer screening within the Slovenian health system, if supported with European recommendations. Key messages • Breast cancer risk assessment entering national screening programme in Slovenia is feasible. • Personalized breast cancer screening could reduce unnecessary mammographies for women at lower risk and reduce the overall screening mammographies workload.