Introduction: Magnetic resonance imaging (MRI) serves as a screening tool for breast cancer in high-risk populations. Background parenchymal enhancement (BPE) and breast density (BD) are normal properties of the fibroglandular tissue and are related to increased breast cancer risk.
Purpose: To compare the extent of BPE and BD at breast MRI: in BRCA gene mutation carriers and non-carriers, and to evaluate their effect on short term follow-up recommendation rate.
Materials and Methods: This was a case-control study. The BPE and BD in MRI studies of known BRCA 1 or BRCA 2 mutations carriers were compared to the studies of age matched non-carrier during the years 2011-2012.
Results: BPE was high in up to one third of women. 22% of the carriers had high BPE, versus 33% of the control group (p-value 0.013). Results were similar when non menstrual cycle timed MRI examinations were excluded. BD was high in most cases: of them 62% of the carriers had high BD versus 75% of the control group (p=0.004). BI-RADS 3 final assessment was more commonly assigned to cases with high BPE levels, and with higher frequency in the control group.
Conclusion: In our study, women who are BRCA mutation carriers had lower BPE and BD levels as compared to an age matched control group. Our results may highlight different risks causing distinctive breast cancer subgroups; hormonal enriched, and mutational defected DNA damage repair, and may affect future consideration upon preventive medical treatment considerations. MRI indication differences (screening in the mutations carrier group versus breast cancer evaluation in the control group) most likely accounted for the more frequent BIRADS 3 final assessment in high BPE levels seen within the control group.
Key words: Breast MRI, Breast density, Background parenchymal enhancement, BRCA gene mutation carriers
