Magnetic resonance imaging was more sensitive than mammography for detecting breast cancer in high-risk women.

M e t h o d s Design: Blinded comparison of MRI and mammography for detecting breast cancer. Setting: 6 familial cancer clinics in the Netherlands. Patients: 1909 women who were 25 to 70 years of age (mean age 40 y) and had a cumulative lifetime risk for breast cancer ≥ 15% because of familial or genetic predisposition. Women < 25 years of age could be tested if they had a family history of breast cancer diagnosed before 30 years of age. Exclusion criteria were symptoms suggestive of breast cancer or personal history of breast cancer. 358 of the women were confirmed carriers of BRCA1, BRCA 2, PTEN, or TP53 genetic mutations. Description of tests: Mammography and a dynamic breast MRI with gadolinium-containing contrast medium were done annually. When one of the tests was scored as “probably benign” or “need additional imaging evaluation,” further investigation was done by ultrasonography (with or without fine-needle aspiration) or by repeating mammography or MRI. When one of the examinations was scored as “suspicious abnormality” or “highly suggestive of malignancy,” a cytologic or histologic evaluation of a biopsy specimen was done. Diagnostic standard: Asymptomatic breast cancer confirmed by biopsy during follow-up of an abnormal mammogram or MRI, or symptomatic breast cancer diagnosed during the period between screenings. {Histologic examinations were blinded to MRI and mammography results.}* Outcomes: Sensitivity and specificity for detecting breast cancer.