An individualized breast cancer risk assessment model for women attending screening in BreastScreen Norway. The large retrospective cohort study included 57,411 women screened in Norway between 2007 and 2019. The study aimed to validate the weight of specific risk factors for breast cancer.

The adjusted hazard ratios (aHR) was estimated for different risk factors including age, breast density, family history of BC, body mass index (BMI), age at menarche, alcohol habit, exercise, pregnancy, hormone replacement therapy (HRT) and benign breast disease (BBD). 

The study showed that “all variables included in the model explained part of the variability in BC risk”. The 4-year BC risk was between 0.22% and 7.43%. Breast density was the variable that had a higher effect in the model