Association between vitamin D deficiency and breast cancer histology: A retrospective database review.

1039 Background: Vitamin D (Vit D) deficiency has been shown to be associated with a higher risk of developing breast cancer. Inverse association has also been shown between vit D level and tumor size. However, the association between vit D deficiency and breast cancer histology remains unclear. Preclinical data has suggested that vit D plays an essential role in the terminal differentiation of breast cells. Thus, we hypothesize that vit D deficiency would be associated with estrogen receptor-negative tumors, particularly triple-negative breast cancers (TNBC) which are associated with aggressive clinical course. Methods: We conducted a retrospective database review to obtain information including age, race, tumor histology, size, stage, and vit D levels in newly diagnosed breast cancer patients at University of Maryland Greenebaum Cancer Center. Results: 150 patients presented between July 2008 and August 2011 were included in this analysis. Average age at diagnosis was 57 (range 30-87), and 56% of patien...