Vitamin D receptor gene polymorphisms, bioavailable 25-hydroxyvitamin D, and hepatocellular carcinoma survival

Little is known about the role of vitamin D receptor polymorphisms and their interaction with vitamin D status in hepatocellular carcinoma (HCC) prognosis.

We evaluated the association of TaqI, BsmI, Cdx-2, and ApaI polymorphisms, individually and in combination, with liver cancer-specific (LCSS) and overall survival (OS) among 967 patients with newly diagnosed HCC. Subsequently, we examined whether these polymorphisms modified the association between serum bioavailable 25-hydroxyvitamin D (25OHD) concentrations and survival. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

During a median follow-up of 1017 days, 393 deaths occurred, with 360 attributed to HCC. Having TaqI G allele (HRper allele = 1.30, 95% CI = 1.08 to 1.57) or BsmI T allele (HRper allele = 1.41, 95% CI = 1.01 to 1.99) was associated with worse LCSS. Carrying increasing numbers of protective alleles was associated with superior LCSS (HR6-8 vs 0-3 = 0.52, 95% CI = 0.34 to 0.80). The inverse association of bioavailable 25OHD with LCSS was statistically significant only in patients with TaqI AA (HRQuartile 4 vs Quartile 1 = 0.63, 95% CI = 0.44 to 0.92), BsmI CC (HRQuartile 4 vs Quartile 1 = 0.62, 95% CI = 0.44 to 0.88), and 6 to 8 protective alleles (HRQuartile 4 vs Quartile 1 = 0.45, 95% CI = 0.23 to 0.87). Similar associations were observed for OS.

Patients carrying wild-type TaqI, BsmI, or more protective alleles had improved survival and might benefit from optimizing bioavailable 25OHD status.