Purpose: To estimate the life years gained by adding breast MRI screening to the screening protocol currently recommended for women who carry a BRCA1 or BRCA2 mutation.

Methods: A Monte Carlo simulation model was developed to reproduce the individual life history of women who carry a BRCA 1 or 2 mutation. Compared to the general population, this population is modeled with an increased risk of breast cancer and ovarian cancer and a higher likelihood of prophylactic bilateral salpingo-oophorectomy. Seventy percent of the women are assumed to carry a BRCA1 mutation and the remaining 30% a BRCA2 mutation. These women are assumed to undergo annual screening mammography from ages 25 to 70, with and without annual breast breast MRI from ages 25 to 50. Screening by either mammography or MRI increases the probability that a given women will be detected at an earlier stage and earlier age. A model of the detection characteristics of the screening examinations combined with a model of the natural history of breast cancer are used to derive the tumor characteristics among BRCA1 and BRCA2 carriers in terms of the detected tumor size, SEER historic stage, grade and ER status. Long term breast cancer survival is based on the tumor characteristics and patient age at detection, and incorporates the benefits of primary and adjuvant treatment.

Results: Relative to annual screening mammography offered to carriers of BRCA1/2 mutations of ages 25 to 70, introducing breast MRI screening as an additional examination from ages 25 to 50, provides an average health benefit of approximately one year of life saved. Extending the age at cessation of breast MRI screening to 55, adds approximately 30 additional days of life.

Conclusions: Adding breast MRI screening to the screening protocol currently recommended for women who carry a BRCA1 or BRCA2 mutation is estimated to provide a positive health benefit as measured in life years.