Model for estimating personalized breast cancer risk after chest radiation for childhood cancer

Analysis in the cohort of the Childhood Cancer Survivor Study resulted in a model for estimating personalized risk of breast cancer in women who had received chest radiation for childhood cancer. The model included current age, chest radiation field, whether chest radiation was delivered within 1 year of menarche, anthracycline exposure, age at menopause, and history of a first-degree relative with breast cancer. Risk estimates ranged from 2% to 23% for 30-year-old women and from 5% to 34% for 40-year-old women. The model was validated in three independent cohorts, with good calibration and an expected-to-observed ratio of the number of breast cancers of 0.92 (95% CI 0.74-1.16).