Michael J DeLeo, III MD, Presenter: Nothing to Disclose

Susan Domchek MD, Abstract Co-Author: Nothing to Disclose

Despina Kontos PhD, Abstract Co-Author: Research Consultant, Hologic, Inc Support agreement, Hologic, Inc

Emily F. Conant MD, Abstract Co-Author: Consultant, Hologic, Inc

Susan Pae Weinstein MD, Abstract Co-Author: Nothing to Disclose

Bilateral salpingo-oophrectomy (BSO) reduces breast cancer risk in women with BRCA1/2 mutations by approximately 50%. Annual screening for these high-risk women includes breast MRI and mammography. It is unknown whether BSO affects fibroglandular volume (FG) and background enhancement (BG) on breast MRI in this population. The purpose of this study is to assess the difference in FG and BG in BRCA1/2 mutation carriers before and after BSO on breast MRI.

We compared FG and BG on contrast-enhanced breast MRI before and after BSO. Two readers blinded to both clinical and imaging history scored FG according to the BI-RADS criteria from 1-4: fatty, scattered, heterogeneously dense, or extremely dense. BG was graded based on the MRI BI-RADS scale from 1-4: minimal, mild, moderate, and marked. Average BI-RADS scores of each reader were used to calculate mean FG and BG (±SD) before and after BSO, and compared using a paired t-test for significance. 

We examined 48 women with BRCA1/2 mutations who underwent breast MRI before and after BSO from 2001-2011 at our institution. Five patients were excluded from the final analysis as they underwent mastectomy or bilateral radiation therapy before post-BSO MRI. Mean time to post-BSO MRI was 6.7 months ± 4.4 months. Mean pre- and post-operative FG were 2.74±0.81 and 2.69±0.77, respectively (p=0.825). Mean pre- and post-operative BG were 2.63±0.88 and 1.92±0.86, respectively (p<0.001). Breast cancer was detected in 5 women at a median time of 3.4 years following BSO. In these 5 women, mean pre- and post-operative FG were 3.08±0.66 and 2.58±0.80, respectively. Mean pre- and post-operative BG were 2.92±0.66 and 2.33±0.75, respectively.

In this population of 43 BRCA1/2 mutation carriers who underwent breast MRI before and after BSO, there was a statistically significant reduction in BG following BSO, and there was no significant difference in FG. For the 5 patients in this cohort who were diagnosed with breast cancer after BSO, there was a trend toward higher FG and BG both before and after BSO, in comparison to the patients who were not diagnosed with breast cancer, suggesting that rates of higher FG and BG may be associated with increased risk for developing breast cancer.

Reduction in BG following BSO could be used as an additional risk-stratification measure in patients with BRCA1/2 mutations, rather than using fibroglandular volume.

DeLeo, III, M, Domchek, S, Kontos, D, Conant, E, Weinstein, S, Breast MRI Parenchymal Enhancement and Fibroglandular Volume in BRCA1/2 Mutation Carriers Before and After Bilateral Salpingo-Oophrectomy.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12024853.html