The Relationship Between Vitamin D Level and Prognostic Factors in Patients Diagnosed with Breast Cancer

Background: To examine the relationship between vitamin D level at the time of diagnosis and disease prognostic factors in patients diagnosed with breast cancer. Materials and Methods: We studied 150 patients with breast cancer whose vitamin D levels were measured before treatment. The patients’ vitamin D levels were compared with their estrogen receptor (ER) levels, progesterone receptor (PR) levels, human epidermal growth factor receptor 2 (Her-2/neu) status, ki-67 levels, and histopathological features. Results: Vitamin D was found to be significantly positively correlated with ER (p<0.001) and PR (p=0.032) staining intensities and significantly negatively correlated with ki-67 level (p=0.001). Both the ER (p=0.003) and ki-67 index (p=0.024) were found to be significantly correlated with vitamin D level, 20 ng/mL below and above, and its relation with prognostic factors. Conclusion: There may be a relationship between serum 25 hydroxy vitamin D [25(OH)D] level and breast cancer prognosis. Our study can be used as a guide for examining the contribution of supportive treatments that provide normal vitamin D levels (>30 ng/mL) to decrease breast cancer aggressiveness. More studies are needed to elucidate the relationship between breast cancer and vitamin D.