Background: High breast density is an independent risk factor for breast cancer as well as benign breast diseases. However there are few studies about breast density of ductal carcinoma in situ (DCIS) and benign breast disease(BBD). In this study, we investigated patterns of breast density of DCIS and BBD, and comparatively analyzed breast densities of DCIS and BBD.

Material and Methods From 2008 to 2009, 345 patients underwent surgery for DCIS at Asan Medical Center, and 295 patients for BBD at 2010. We retrospectively reviewed each groups and estimated cranio-caudal view of digital mammogram of unaffected breast by computer-assisted thresholding methods, using Cumulus 4, version 4.0. For BBD we included atypical ductal hyperplasia, fibroadenoma, papilloma(atypical/intraductal), phyllodes tumor(benign/borderline), and excluded unavailable mammogram(mostly, because of scanned films from outside hospitals and previously diagnosed breast cancer).

Results Mean ages of each group were 46.51 year old in DCIS group and 41.43 year old in BBD group, and the mean percentage density(PD) were 44.89% and 45.27%, respectively.

There was no significant difference between two groups in total population(p=0.79). We categorized into two groups according to the age, ≥50 and <50, for each DCIS and BBD group. Mean percentage density of below 50 year old was 52.92% in DCIS gruop and 49.58% in BBD group(p=0.031). Mean percentage density above 50 year old was 33.67% in DCIS group and 33.29% In BBD group(p=0.867).

Conclusion The mean values and distribution patterns of PD were similar between BBD group and DCIS group. However, in the subgroup aged under 50, the DCIS group has significantly higher breast density than the BBD group. Although the causal association of breast density with breast cancer has been relatively well documented, this kind of cross-sectional study has an inherent limitation. The absolute difference between the DCIS group and the BBD group under age 50 (3.34% in table2) needs more investigation for its clinical implications.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-08-06.