A Systematic review of vitamin D pathway genetic variation and Risk of Breast Cancer

Background and Objectives: There has been considerable interest recently on the subject of the potential roleof vitamin D in the primary and secondary prevention of cancer. Studies presented a range of anticarcinogeniceffects for vitamin D compounds on breast cancer. Therefore, we performed a systematic review of the influenceof vitamin D pathway genetic variation on risk of breast cancer.Methods: The databases of PubMed, Scopus, Cochrane, Google Scholar, SID, IranMedex and Magiran until July2017 and reference section of relevant articles, were searched to identify both English and Persian studies onbreast cancer issue that observed the association between vitamin D pathway genetic variation and breast cancerrisk and theirs quality was evaluated by Newcastle-Ottawa Scale (NOS)checklist. A total of 26 studies werefinally included.Results: It has become apparent that the vitamin D receptor (VDR) is expressed in most cells, and that multipletissues have the ability to change the primary circulating form of vitamin D into the active form.Correspondingly, 1,25(OH)2D binds to the VDR (a ligand-dependent transcription factor) and polymorphisms inthe VDR gene have been shown to modify the activity of this Vit D–VDR complex. Moreover, polymorphismsin the VDR gene have been linked to breast cancer risk. VDR expression has been linked to survival in breastcancer and relations were observed between progression-free survival and rs2228570 TT genotype in breastcancer. No association was reported between rs1544410 and breast cancer outcome.Conclusions: Higher 25OHD concentration is associated with better survival in breast cancer, and the observedassociation of functional variants in vitamin D pathway genes with survival supports a causal link. This studyprovides to make researchers to consider the potential beneficial effect of vitamin D in the context of breastcancer.

Keywords:

vitamin D , Genetics , Breast Cancer