Association Between Expression of Vitamin D Receptor and Insulin-Like Growth Factor 1 Receptor Among Breast Cancer Patients

Background: Vitamin D receptor (VDR) and insulin-like growth fac-tor 1 receptor (IGF1R) are known to be involved in breast cancer (BC) progression. Our previous work reported a correlation of dif-ferential localization of IGF1R with hormone receptor status in BC. A recent report described VDR and IGF1R as potential indicators of BC prognosis, but their interplay was not discussed. The present study focused on understanding the association of VDR expression with IGF1R activation, different molecular markers, and subtypes of BC. Methods: A retrospective study was designed to evaluate the VDR ex-pression among 48 BC patients pathologically diagnosed as invasive BC and were surgically treated at Sharjah Breast Care Center, Univer-sity Hospital Sharjah (UHS), United Arab Emirates (UAE). Formalin-fixed paraffin-embedded (FFPE) tumor blocks with appropriate clin-icopathological data were subjected to immunohistochemistry (IHC), and VDR protein expression was interpreted based on the staining intensity (SI) and the percentage of the positively stained cells (PP). Results: Nearly 44% of cases in the study were vitamin D deficient. A positive VDR expression with strong intensity (score > 4) was seen in 27 cases (56.3%). The expression pattern for VDR was equally dis-tributed in cytoplasm and nucleus. For the IGF1R intensity, 24 cases (50%) of total cohort showed strong expression. A significant associa-tion was detected between IGF1R and VDR expression (P = 0.031). Conclusions: The present study identified positive association be-tween IGF1R and VDR expression where most of the cases with strong VDR expression displayed strong IGF1R expression. These findings may contribute to current understanding on the role of VDR in BC and its interaction with IGF1R.