High-risk breast cancer screening with MRI: diagnostic performance of a local scoring system

Breast MRI is widely used for screening high-risk women, though its high cost and false positive rates pose challenges. There is growing research exploring the potential integration of breast MRI into the screening of other patient groups, including women with dense breasts and/or an intermediate lifetime risk for breast cancer. We evaluated the diagnostic performance of Leicester scoring system (LSS) in managing lesions detected at high-risk screening breast MRI.

In this retrospective study, 73 lesions from 174 high-risk breast MRI studies over a 10-year period (2014-2024) were analyzed. Included lesions were masses, foci, and linear/ductal non-mass-like enhancement. Lesions were classified and scored using the LSS, which combines five MRI descriptors: margins, signal patterns, internal enhancement, contrast kinetics, and DWI patterns.

All 10 malignant lesions had LSS scores ≥2 (mean: 4.6). Of the 40 benign lesions (excluding IMLNs), 87.5% had scores <2 (mean: 1.1). The optimal cut-off of 2 achieved 100% sensitivity and 87.5% specificity (p<0.001). Typical IMLNs, which often mimic malignancy on imaging, should be excluded from scoring and considered benign when they are not significant by size criteria. Using LSS could potentially avoid biopsy in 48% of lesions, or up to 79% if IMLNs are excluded, without missing any cancers. The inter-reader agreement was very good, with a K-value of 0.81 (p<0.001).

Leicester Scoring System has the potential to avoid up to 79% of unnecessary biopsies without compromising cancer detection. Our results challenge the assumption that cancers may present with exclusively benign features in this cohort of women.