Abstract P4-01-07: The Relationship of Breast Density in Mammography and Magnetic Resonance (MR) Imaging in a High Risk Population

Abstract

Abstract Background: Mammographic breast density (BD) is associated with a 4 to 6-fold increased risk for developing breast cancer. Increased breast density on mammography is also known to decrease the diagnostic sensitivity of the exam, which is of great concern to women at increased risk for breast cancer. There is well-established medical literature describing the benefit of MRI in screening high risk women. A previous study has shown that background parenchymal enhancement (BPE) as measured on MRI can be correlated with breast cancer risk. The purpose of this study was to evaluate the relationship between BD, BPE, and FGT (assessment of the amount of fibroglandular tissue with contiguous MR images through both breasts) in pre and post-menopausal women who are at high risk for developing breast cancer. Methods: The High Risk Breast Cancer Consortium (HRBCC) database at NYU Langone Medical Center was queried for our study population. A total of 56 women had both screening mammograms and MRIs completed at our center. Variables of interest included BD, BPE, FGT, BMI, Gail scores, and menopausal status. BD was defined by ACR classifications 1–4. FGT was assessed on a similar scale 1–4. BPE was categorized as minimal, mild, moderate, or marked. BMI (kg/m2) was grouped into 4 categories: underweight (≤18), normal (19–24), overweight (25–29), and obese (≥30). Statistical analyses were performed using Spearman Correlation Coefficients. Results: The median age in our cohort was 48 years (range 24–70 years). The majority of women were Caucasian (74%) with a median 5-year Gail score of 3.35. There was no correlation between BD and BPE (r = 0.08) and BPE and FGT (r = 0.18). However, there was a moderate positive correlation between BD and FGT (r = 0.65). When we stratified by menopausal status, the correlation for BD and FGT was stronger for post-menopausal women (r = 0.73) versus premenopausal women (r = 0.57). When we stratified by BMI, we found a stronger positive association for BD and FGT among women who were overweight and obese (r = 0.62). Conclusions: In our study cohort of patients at high risk for developing breast cancer, BD and BPE were not correlated, even after adjusting for menopausal status. This implies that BD and BPE may represent different characteristics of breast tissue and may have different implications. We found a strong correlation between BD and FGT. This association was strongest in women who were overweight and obese. FGT is a more objective and quantitative measurement of breast density and may be more useful in quantitative breast cancer risk assessment. Further studies are necessary to determine if BPE and FGT are independent risk factors for breast cancer. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-01-07.