Prevalence and Predictive Value of BI-RADS 3, 4, and 5 Lesions Detected on Breast MRI: Correlation with Study Indication

Prevalent versus incident breast cancers: benefits of clinical and radiological monitoring in women with pathogenic BRCA1/2 variants

Women with pathogenic germline BRCA1 or BRCA2 variants have a higher risk of breast cancer than in the general population. International guidelines recommend specific clinical and radiological breast follow-up. This specific breast screening program has already been shown to be of clinical benefit, but no information is available concerning the use of prognostic factors or specific survival to guide follow-up decisions. We evaluated "high-risk" screening in a retrospective single-center study of 520 women carrying pathogenic germline variants of the BRCA1 or BRCA2 gene treated for breast cancer between January 2000 and December 2016. We compared two groups of women: the incidental breast cancer group (IBCG) were followed before breast cancer diagnosis (N = 103), whereas the prevalent breast cancer group (PBCG) (N = 417) had no specific follow-up for high risk before breast cancer diagnosis. Breast cancers were diagnosed at an earlier stage in the IBCG than in the PBCG: T0 in 64% versus 19% of tumors, (p < 0.00001), and N0 in 90% vs. 75% (p < 0.00001), respectively. Treatment differed significantly between the 2 groups: less neoadjuvant chemotherapy (7.1% vs. 28.5%, p < 0.00001), adjuvant chemotherapy (47.7% vs. 61.9%, p = 0.004) and more mastectomies (60% vs. 42% p < 0.0001) in the IBCG vs PBCG groups respectively. Overall and breast cancer-specific mortality were similar between the two groups. However, the patients in the IBCG had a significantly longer metastasis-free survival than those in the PBCG, at three years (96.9% [95% CI 93.5-100] vs. 92.30% [95% CI 89.8-94.9]; p = 0.02), suggesting a possible long-term survival advantage.

Current and Future Directions of Breast MRI

Magnetic resonance imaging (MRI) is the most sensitive exam for detecting breast cancer. The American College of Radiology recommends women with 20% or greater lifetime risk of developing breast cancer be screened annually with MRI. However, other high-risk populations would also benefit. Hartmann et al. reported women with atypical hyperplasia have nearly a 30% incidence of breast cancer at 25-year follow-up. Women with dense breast tissue have up to a 4-fold increased risk of breast cancer when compared to average-risk women; their cancers are more likely to be mammographically occult. Because multiple cohorts of women are at high risk for developing breast cancer, there has been a movement to develop an abbreviated MRI (abMRI) protocol to expand the availability of MRI screening. Studies on abMRI effectiveness have been promising, with Weinstein et al. demonstrating a cancer detection rate of 27.4/1000 in women with dense breasts after a negative digital breast tomosynthesis. Breast MRI is also used to evaluate the extent of disease as part of preoperative assessment in women with newly diagnosed breast cancer, and to assess a patient's response to neoadjuvant chemotherapy. This paper aims to explore the current uses of MRI and propose future indications and directions.

Subclassification of BI-RADS 4 Magnetic Resonance Lesions: A Systematic Review and Meta-Analysis

OBJECTIVE

This research aims to investigate and evaluate the diagnostic efficacy of magnetic resonance imaging (MRI) in classifying Breast Imaging Reporting and Data System (BI-RADS) 4 lesions into subcategories: 4a, 4b, and 4c, so as to limit biopsies of suspected lesions in the breast.

METHODS

The PubMed, Web of Science, Embase, and Cochrane Library foreign language databases were searched for literature published between January 2000 and July 2018. After analyzing the selection, data extraction, and quality assessment, a meta-analysis was performed, including data pooling, heterogeneity testing, and meta-regression.

RESULTS

Fourteen articles, including 18 studies, met the inclusion criteria. The diagnostic efficacy of MRI for BI-RADS 4-weighted summary assay sensitivity and specificity were estimated at 0.95 [95% confidence interval (CI), 0.89-0.98] and 0.87 (95% CI, 0.81-0.91), respectively. The positive and negative likelihood ratios were 7.1 (95% CI, 4.7-10.7) and 0.06 (95% CI, 0.02-0.14), respectively. The diagnostic odds ratio was 126 (95% CI, 37-426), and the area under the receiver operating characteristic curve was 0.95 (95% CI, 0.93-0.97). The malignancy ratio of BI-RADS 4a, 4b, and 4c and malignancy range were 2.5% to 18.3%, 23.5% to 57.1%, and 58.0% to 95.2%, respectively.

CONCLUSION

Risk stratification of suspected lesions (BI-RADS categories 4a, 4b, and 4c) can be achieved by MRI. The MRI is an effective auxiliary tool to further subclassify BI-RADS 4 lesions and prevent unnecessary biopsy of BI-RADS 4a lesions.

American College of Radiology Accreditation, Performance Metrics, Reimbursement, and Economic Considerations in Breast MR Imaging

Accreditation through the American College of Radiology (ACR) Breast Magnetic Resonance Imaging Accreditation Program is necessary to qualify for reimbursement from Medicare and many private insurers and provides facilities with peer review on image acquisition and clinical quality. Adherence to ACR quality control and technical practice parameter guidelines for breast MR imaging and performance of a medical outcomes audit program will maintain high-quality imaging and facilitate accreditation. Economic factors likely to influence the practice of breast MR imaging include cost-effectiveness, competition with lower-cost breast-imaging modalities, and price transparency, all of which may lower the cost of MR imaging and allow for greater utilization.