An exploratory analysis of common genetic variants in the vitamin D pathway including genome-wide associated variants in relation to glioma risk and outcome

Abstract

Purpose: Experimental and epidemiological evidence shows a beneficial role of vitamin D in cancer. In vitro evidence is consistent with a similar protective function in glioma; however, no study has yet examined the potential role of vitamin D in glioma.

Methods: We evaluated the association between common genetic variants in the vitamin D pathway and glioma risk and patient outcome in 622 newly diagnosed glioma cases and 628 healthy controls enrolled in a clinic-based case-control study. Subjects were genotyped for 7 candidate and tagging single nucleotide polymorphisms in the vitamin D receptor and 8 additional variants in NADSYN1, GC, CYP24A1, CYP2R1, and C10ORF88 linked in genome-wide association studies to serum concentrations of vitamin D. Unconditional logistic regression was used to estimate age- and gender-adjusted odds ratios and 95 % confidence intervals for glioma risk according to vitamin D genotypes. Proportional hazards regression was used to estimate hazard ratios for glioma-related death among 320 patients diagnosed with high-grade tumors. P values were uncorrected for multiple comparisons.

Results: Risk of astrocytic tumors was associated with variant alleles in rs3829251 (NADSYN1), rs10741657 (CYP2R1), rs2228570 (Fok1, VDR), and rs731236 (Taq1, VDR). No risk associations were found among oligodendroglial tumors. Survival associations were observed according to variant status for rs1544410 (Bsm1, VDR) and rs6013897 (CYP24A1).

Conclusion: This exploratory analysis provides limited evidence of a role for genetic variation in vitamin D pathway genes with glioma risk and survival.