Screening with magnetic resonance imaging, mammography and ultrasound in women at average and intermediate risk of breast cancer.

Background: The addition of MRI to mammography and ultrasound for breast cancer screening has been shown to improve screening sensitivity for high risk women, but there is little data to date for women at average or intermediate risk.

Methods: Two thousand nine hundred and ninety-five women, aged 40 to 65 years with no previous history of breast cancer were enrolled in a screening program, which consisted of two rounds of MRI, ultrasound and mammography, one year apart. Three hundred and fifty-six women had a mutation, 370 women had a first-degree relative with breast cancer (and no mutation) and 2269 women had neither risk factor.