Association of Serum Vitamin D Level and Vitamin D Receptor Expression among Newly Diagnosed Breast Cancer

There is a mushrooming interest in the anti-carcinogenic property of vitamin D. However, many researches reported a conflicting result in the association of vitamin D levels to certain types of cancer. This study was designed to assess the association between vitamin D and vitamin D receptor (VDR) expression with breast cancer. This case-control study, carried out at Hospital Universiti Sains Malaysia, Kelantan, involved 69 newly diagnosed breast cancer patients and 73 healthy volunteers. Serum 25(OH)D was taken and compared between 2 groups. VDR expression in patients' breast tissue samples was determined by immunohistochemical staining method using anti-VDR antibody. 85.5% of breast cancer patients and 97.3% of healthy control were vitamin D insufficient with a mean (SD) of 13.36 (6.96) ng/mL and 13.05 (3.71) ng/mL, respectively, and the difference was not statistically significant. VDR expression showed cytoplasmic positivity in 75.4% of breast cancer tissue, followed by both cytoplasmic and nuclear positivity in 21.5% and complete absence in 3%. There was no significant association between VDR expression and hormone receptor status. In conclusion, there was a high prevalence of vitamin D deficiency among breast cancer and healthy volunteers in our study. There was no significant association between breast cancer and vitamin D. The VDR expression in breast cancer cells showed high cytoplasmic localization.