Accuracy and Surgical Impact of Magnetic Resonance Imaging in Breast Cancer Staging: Systematic Review and Meta-Analysis in Detection of Multifocal and Multicentric Cancer

Abstract

Purpose: We review the evidence on magnetic resonance imaging (MRI) in staging the affected breast to determine its accuracy and impact on treatment. Methods: Systematic review and meta-analysis of the accuracy of MRI in detection of multifocal (MF) and/or multicentric (MC) cancer not identified on conventional imaging. We estimated summary receiver operating characteristic curves, positive predictive value (PPV), true-positive (TP) to false positive (FP) ratio, and examined their variability according to quality criteria. Pooled estimates of the proportion of women whose surgery was altered were calculated. Results: Data from 19 studies showed MRI detects additional disease in 16% of women with breast cancer (N = 2,610). MRI incremental accuracy differed according to the reference standard (RS; P = .016) decreasing from 99% to 86% as the quality of the RS increased. Summary PPV was 66% (95% CI, 52% to 77%) and TP:FP ratio was 1.91 (95% CI, 1.09 to 3.34). Conversion from wide local excision (WLE) to mastectomy was 8.1% (95% CI, 5.9 to 11.3), from WLE to more extensive surgery was 11.3% in MF/MC disease (95% CI, 6.8 to 18.3). Due to MRI-detected lesions (in women who did not have additional malignancy on histology) conversion from WLE to mastectomy was 1.1% (95% CI, 0.3 to 3.6) and from WLE to more extensive surgery was 5.5% (95% CI, 3.1 to 9.5). Conclusion: MRI staging causes more extensive breast surgery in an important proportion of women by identifying additional cancer, however there is a need to reduce FP MRI detection. Randomized trials are needed to determine the clinical value of detecting additional disease which changes surgical treatment in women with apparently localized breast cancer.