Objective: Squamous cell carcinoma (SCC) of the urinary bladder is associated with aggressive behavior and is typically treated with radical cystectomy. Vitamin D receptor (VDR) and its ligand Calcitriol have shown anti-tumor effects in various malignancies but to our knowledge there is no current information on VDR expression in bladder SCC. This study aimed to assess VDR immunostaining patterns in pure bladder SCC and its relation to the available clinicopathological parameters of such tumors.

Material and Methods: VDR immunostaining was performed on 35 radical cystectomy specimens from patients with primary pure SCC. Nuclear and cytoplasmic VDR staining was scored separately using the semi-quantitative immunoreactive score.

Results: Nuclear and cytoplasmic/membranous VDR expression was present in 35 (100%) and 19 (54.3%) cases, respectively, with a significant negative linear relationship (r=-0.33; p=0.035). Differences in cytoplasmic/membranous VDR expression were found in relation to tumor histology (p=0.018), tumor necrosis (p=0.022), and stage groups (p=0.001). Low cytoplasmic VDR correlated with increased tumor staging (Cc = -0.422), positive lymph node status (Cc = -0.375), and higher stage groups (Cc= -0.438). The median nuclear VDR expression score was significantly higher in advanced stage groups (p= 0.038).

Conclusion: Our data suggest that VDR may be a potential prognostic factor in bladder SCC. Further studies and clinical trials using vitamin D supplements may provide a new therapeutic option for those high-risk patients.