MTHFR polymorphisms in relation to ovarian cancer risk.

OBJECTIVE Folate has been hypothesized to influence carcinogenesis due to its dual role in DNA methylation, which regulates gene expression, and synthesis of purine and thymidylate, which is vital for DNA repair. Thus, we examined ovarian cancer risk in relation to two functional polymorphisms (C677T and A1298C) in the MTHFR gene. METHODS We genotyped the C677T (rs1801133) and A1298C (rs1801131) MTHFR polymorphisms in 1642 cases and 2068 controls from three studies, the New England Case Control Study (NEC), Nurses' Health Study (NHS), and Mayo Clinic Ovarian Cancer Case Control Study (MAY). RESULTS Overall, we observed no association between either SNP and ovarian cancer risk (pooled C677T p(trend)=0.59 and A1298C p(trend)=0.58). Significant associations (C677T p(trend)=0.001, A1298C p(trend)=0.02) between these MTHFR SNPs and serous ovarian cancer risk were observed in the NEC study, but were not replicated in the NHS and MAY studies. CONCLUSIONS MTHFR SNPs C677T and A1298C are not associated with ovarian cancer risk. Our results highlight the need for validation of genetic findings.