Higher volumetric breast density to predict risk for aggressive breast cancer subtype in postmenopausal Korean women.

Abstract

e11584 Background: In Asian population, the peak incidence of breast cancer is women in their late forties. We investigated the association between volumetric breast density and breast cancer risk according to menstruation status and breast cancer subtypes in Korean women. Methods: We prospectively enrolled 509 newly diagnosed breast cancer patients and 1336 healthy control subjects who performed mammography at the National Cancer Center in Korea between Sep 2011 and Nov 2012. Breast density was estimated using volumetric breast composition measurement (VolparaTM). We collected clinical data including menstruation status, parity, BMI and use of postmenopausal hormones. For cancer patient, we additionally acquired following pathologic data: histologic type, tumor size and grade, receptor status, Ki-67, and nodal status. Results: Of a total of subjects, 1064 (57.7%) women were postmenopausal status. The risk of breast cancer increased progressively with increase in volumetric breast density (Ptrend <0.001) in all subjects. In addition, breast cancer risk increased in women < 60 years old (odds radio (OR) = 1.81), higher body mass index (BMI) (< 25kg/m2 vs. ≥ 25kg/m2) (OR = 2.41), and fewer childbirth (0/1 vs. ≥ 2) (OR=2.38). In postmenopausal women, higher breast density (category 4) showed a 3.00-fold (OR = 3.00, 95% confidence interval (CI) = 1.75-5.16, P<0.001) increased risk of breast cancer compared with lower breast density (category 1-2). In contrast, there was no such association in premenopausal women. The associations of volumetric breast density were stronger for HER2 positivity (Ptrend <0.019), and high Ki-67 (Ptrend <0.006) in postmenopausal breast cancer patients. There was a statistically significant association between lower breast density and hormone receptor (HR) positive/HER2 negative breast cancer (Ptrend <0.019). Conclusions: High volumetric breast density is associated with the risk of breast cancer having more aggressive tumor characteristics in postmenopausal women.