The validation of a simulation model incorporating radiation risk for mammography breast cancer screening in women with a hereditary-increased breast cancer risk.

INTRODUCTION For women with a BRCA1 or BRCA2 mutation or a strong family history of breast cancer, there is no clear estimation of the risk of tumour induction versus the beneficial effects of mammography screening available. This study aims to validate the Simulation Model on Radiation Risk and breast cancer Screening (SiMRiSc) model in these women, which can provide information on the benefits and risks of screening for breast cancer for various screening scenarios. METHODS The simulation model for breast cancer screening was developed and the values for model parameters including cancer induction due to radiation were derived from the literature. The simulation model was validated by comparing the outcome data of the model with the data from three published screening studies of women with an increased hereditary breast cancer risk. A sensitivity analysis was used to estimate the error margins of the outcome data and to analyse the sensitivity of the simulation model to each parameter. RESULTS The model predicted 71+/-4% of the reported tumours. When excluding the excess number of incident tumours detected in the first screening round, the model predicted 85+/-6% of the tumours reported. The model was most sensitive to changes in the parameters related to lifetime breast cancer risk and sensitivity of mammography. CONCLUSIONS We conclude that the simulation model is suitable for the provision of accurate benefits' and risks' estimations necessary for the refinement of the screening guidelines for women at an increased risk of breast cancer.