MTHFR polymorphisms and ovarian cancer risk: a meta-analysis.

The C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) have been reported to alter the risk of ovarian cancer. However, the results are still inconclusive. For better understanding of the effect of these two polymorphisms on ovarian cancer risk, a meta-analysis was performed. An extensive search was performed to identify all case-control studies investigating such association. The strength of association between these two polymorphisms and ovarian cancer risk was assessed by odds ratio (OR) with the corresponding 95 % confidence interval (95 % CI). 3,496 cases and 3,631 controls for C677T polymorphism and 3,280 cases and 3,346 controls for A1298C polymorphism were included in this meta-analysis. The results suggested that there were no significant associations between C677T and A1298C polymorphisms and ovarian cancer risk in overall comparisons in all genetic models (For C677T: TT vs. CC: OR = 0.94, 95 % CI = 0.71-1.24, P = 0.65; CT vs. CC: OR = 1.03, 95 % CI = 0.93-1.14, P = 0.57; TT/CT vs. CC: OR = 1.01, 95 % CI = 0.88-1.16, P = 0.87; TT vs. CC/CT: OR = 0.93, 95 % CI = 0.72-1.20, P = 0.58. For A1298C: CC vs. AA: OR = 1.05, 95 % CI = 0.88-1.25, P = 0.65; CA vs. AA: OR = 0.98, 95 % CI = 0.88-1.08, P = 0.66; CC/CA vs. AA: OR = 0.99, 95 % CI = 0.90-1.09, P = 0.85; CC vs. AA/CA: OR = 1.06, 95 % CI = 0.90-1.26, P = 0.46). Subgroup analysis based on ethnicities and influence analysis did not perturb the results. In conclusion, the results of this meta-analysis indicate that the MTHFR C677T and A1298C polymorphisms are not associated with ovarian cancer risk, especially in Caucasians.