Expression of vitamin D receptor as a potential prognostic factor and therapeutic target in pancreatic cancer

Aims Vitamin D insufficiency and deficiency are common among patients with pancreatic carcinoma, but epidemiological studies have shown inconsistent results for vitamin D intake/circulation level and pancreatic cancer risk. The study aims were to investigate the effects of vitamin D on patient survival, and the proliferation or survival of pancreatic cancer cell lines. Methods and results The present study examined the local expression of vitamin D receptor (VDR) in pancreatic normal and tumour tissues from a cohort of 61 patients, and analysed the potential correlation between VDR and pathological characteristics, including disease prognosis. Among 61 pairs of normal and tumour specimens, VDR was detected in all normal tissues, and was abundantly expressed in 62.5% (15/24) of tumour tissues with high differentiation, but had a significantly lower or undetectable expression level in 75.7% (28/37) of tissues with moderate or low differentiation (P = 0.004). Moreover, high VDR expression was detected in 63.6% (14/22) of small tumours (≤25 mm) and in only 25.6% (10/39) of large tumours (>25 mm) (P = 0.06). Kaplan–Meier analysis showed that a low level of VDR expression in tumour tissues was associated with a poor prognosis (P = 0.037). Conclusions VDR expression could be a potential prognostic factor for patients with pancreatic adenocarcinoma, and its effects should be examined in a prospective study. Vitamin D analogues may provide a therapeutic choice for patients with high VDR expression in tumours but a low vitamin D level in the circulation.