Vitamin D receptor polymorphisms and cancer

Area of Science:

• Genetics
• Oncology
• Molecular Biology

Background:

• Vitamin D plays a role in cancer development.
• The vitamin D receptor (VDR) mediates vitamin D's cellular effects.
• VDR gene polymorphisms are hypothesized to influence cancer risk, but evidence is conflicting.

Purpose of the Study:

• To systematically review the literature on VDR gene polymorphisms and various cancer types.
• To analyze the association between specific VDR polymorphisms (Fok1, Bsm1, Taq1, Apa1, Cdx2) and cancer risk.

Main Methods:

• Systematic literature review up to June 2012.
• Inclusion of 79 independent studies with 52,427 cases and 62,225 controls.
• Analysis of VDR polymorphisms in relation to skin, ovarian, renal, bladder, lymphoma, leukemia, thyroid, esophageal, liver, sarcoma, and head and neck cancers.

Main Results:

• Significant associations between VDR polymorphisms and prostate, breast, colon-rectum, and skin cancers were reported.
• Conflicting data exists for most cancer types, preventing definitive conclusions.
• Limited studies reported risk estimates for other cancer sites.

Conclusions:

• VDR polymorphisms may modulate the risk for certain cancer types.
• Interactions with calcium and vitamin D intake, 25(OH)D levels, and UV exposure are likely important.
• Future studies should integrate VDR genetic variation with prediagnostic vitamin D status indicators.