Relationship of vitamin D receptor expression with hormone receptors and other clinicopathological features in primary breast carcinomas: A retrospective cross-sectional study

Breast cancer is a heterogeneous disease in which estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 play crucial roles in molecular subtyping, diagnosis, treatment, and prognosis, showing positivity in nearly 90% of cases. The vitamin D receptor (VDR) has been implicated in the oncogenesis and prognosis of various tumors, but its relationship with molecular subtyping factors in breast carcinomas remains to be clarified. This retrospective cross-sectional study included 111 patients who underwent surgery for breast carcinoma. Clinicopathological data were retrospectively analyzed in relation to VDR expression. Histological grade, hormone receptor (HR) status, Ki-67 proliferation index, and other clinicopathological parameters were recorded and their associations with VDR expression were statistically evaluated. Histological grading showed grade 1 in 3.7%, grade 2 in 41.4%, and grade 3 in 54.9% of cases. HR positivity was found in 60.3% of patients, while 39.7% were HR-negative. Ki-67 expression was ≥20% in 65.7% and <20% in 34.3% of cases. VDR expression was low in 54%, moderate in 26.1%, and high in 19.9% of patients. A strong correlation (P < .001) was observed between VDR expression and ER, PR, HR, and Ki-67, while a significant association (P = .025) was found with necrosis and mortality. Additionally, no significant correlation with histological grade (P = .056) was noted. The findings suggest a strong association between VDR and ER, PR status, and the Ki-67 proliferation index in breast carcinoma. Further studies are needed to explore the diagnostic, prognostic, and therapeutic implications of VDR in breast cancer.