MRI MAMMOGRAPHY FOR HIGH RISK INDIVIDUALS

In a single-center study reported in the Journal of Clinical Oncology, Riedl et al found that screening with magnetic resonance imaging (MRI) had greater sensitivity for detection of breast cancer in high-risk women vs mammography or ultrasound irrespective of age, mutation status, or breast density. The addition of mammography or ultrasound added little to the sensitivity of MRI.

Study Details

In the study, BRCA mutation carriers and women with a high familial risk (> 20% lifetime risk) for breast cancer were offered screening with mammography, ultrasound, and MRI every 12 months at the Medical University of Vienna. Overall, 559 women with 1,365 complete imaging rounds were included in the analyses. There were 204 suspicious findings (15%). Of these, 38 (19%) were malignant; two additional cancers were found during the study period, including one identified by patient-requested biopsy and one interval cancer.

Sensitivity

The sensitivity of MRI (90.0%) was significantly greater (P < .001) than that of mammography (37.5%) and ultrasound (37.5%). Of the 40 cancers, 18 (45.0%) were detected by MRI alone, 2 by mammography alone, and 0 by ultrasound alone. Of 14 ductal carcinomas in situ, all were detected by MRI, and 5 (37.5%) each were detected by mammography and ultrasound. Sensitivities were not significantly improved with the addition of ultrasound (90%), mammography (95%), or both (95%) to MRI or with the combination of ultrasound and mammography (50%). In subgroups dichotomized by screening round, mutation status, age, and breast density, the sensitivity of MRI was always greater than that with mammography or ultrasound (largest P = .017).

Specificity

Overall, 166 suspicious imaging findings were false-positives either by biopsy (n =158) or due to absence at biopsy and follow-up (n = 8). Of these, 147 (89%) were suspicious on MRI, 38 (23%) on mammography, and 41 (25%) on ultrasound. The specificity of MRI (89%) was significantly lower (P < .001) than that of ultrasound (97%) and mammography (97%), and was lower than that with the other two modalities in all subgroups dichotomized by screening round, mutation status, and age (P < .001 in all subgroups). 

Of the158 histopathologically confirmed false-positive results, 49 (31%) were atypical ductal hyperplasia. Of these, MRI detected 46 (94%), mammography 12 (24.5%), and ultrasound 8 (16%; P <.001); overall, 46 (31%) of 147 false-positive MRI findings were atypical ductal hyperplasia.

The investigators concluded: “MRI allows early detection of familial breast cancer regardless of patient age, breast density, or risk status. The added value of mammography is limited, and there is no added value of ultrasound in women undergoing MRI for screening.”

Christopher C. Riedl, MD, of Medical University Vienna–General Hospital Vienna, is the corresponding author for the Journal of Clinical Oncology article.

The study was supported by the Funds of the Mayor of Vienna for Medical Science and the Anniversary Fund of the Austrian National Bank. For full disclosures of the study authors, visit jco.ascopubs.org.