Although the antiproliferative and differentiating properties of vitamin D have been demonstrated, its effects on cancer cells are variable. Little is known about vitamin D receptor (VDR) levels in patients with ovarian cancer. In this population we sought to determine correlations between VDR expression, clinical parameters and treatment outcome.
We analyzed VDR content in platelets of healthy women and of a cohort of patients with ovarian tumors and we evaluated possible correlations with clinical parameters, tumor characterization (stage, histology, nuclear grading, ascites), response to therapy and survival. Moreover receptor expression was evaluated immunohistochemically on tissue samples.
VDR levels were markedly lower in healthy women when compared with the pathological group. In the latter a significant increase in receptor expression was observed in malignancies compared with benign cases. No correlation existed between VDR expression and clinicopathological parameters, although we observed an advantage on survival if patients had a higher level of VDR expression in platelets. A cytoplasmic localization of the protein was observed by immunohistochemistry in ovarian cancer cells.
Vitamin D receptor status measured in platelets differs significantly between healthy and pathological groups, increasing with malignancy, and there is a trend towards longer overall survival for tumors showing higher VDR levels. These data suggest that platelet VDR content could be used as a pathological marker. The meaning of this increased VDR expression in platelets needs further investigation and it is possibly linked to an inflammatory response.