Rilian Kaligis Mandang Walukow1 | Hantoro Ishardyanto2 | Willy Sandhika3
VDR is a hormone receptor that mediates the regulatory function of vitamin D in proliferation and differentiation. This VDR activity can affect the regulation of several types of vitamin D functions and activities related to cancer in humans. Also, VDR expression can describe the response of tumor cells to 1,25-dihydroxy vitamin D3 (calcitriol). Based on this thinking, several studies conducted to identify VDR in tumor tissue by immunohistochemical examination are a good method and become a modality for the development of targeted therapies, especially breast cancer metastases. The purpose of this study to determine whether there are differences in the expression of vitamin D receptors in breast cancer tissue with bone metastasis and non-metastatic bone. This research was observational analytic with cross sectional design. The study samples were paraffin blocks of female patients who had been diagnosed with Stage III and IV breast cancer in Dr Soetomo Regional Hospital Surabaya from July to September 2019 who met the study inclusion and exclusion criteria. The independent variables of this study were vitamin D receptors and breast cancer patients who experienced bone metastasis and did not experience metastasis (radiologically proven) as the dependent variable. It was found that there were significant differences in mean VDR expression between groups of breast cancer patients who experienced bone metastasis and those who were non-metastatic (p = 0.001). This shows that breast cancer patients with low VDR expression will experience higher bone metastases and vice versa. There are differences in the expression of VDR in breast cancer tissue with bone metastasis and non-metastatic bone. This study found a statistically significant relationship between VDR expression and the incidence of bone metastases in breast cancer.
Keywords: Breast cancer, Vitamin D, Bone metastasis