Purpose: Published data on the association between manganese superoxide dismutase (MnSOD) Val(16)Ala polymorphism and prostate cancer (PCA) risk are inconclusive. To derive a more precise estimate of the association between them, a meta-analysis was performed.
Methods: PubMed and Embase were searched. All eligible studies were retrieved. The pooled odds ratio (OR) with 95% confidence interval (CI) for PCA risk associated with Val/Ala versus Val/Val, Ala/Ala versus Val/Val, dominant model (Ala/Ala + Val/Ala vs. Val/Val), and recessive model (Ala/Ala vs. Val/Ala + Val/Val) were estimated, respectively.
Results: A total of 12 studies including 8,962 subjects were involved in this meta-analysis. Overall, the meta-analysis indicated that significantly elevated cancer risk was associated with Ala variant genotype when all the eligible studies were pooled into the meta-analysis (for Val/Ala vs. Val/Val: OR = 1.11, 95% CI = 1.00-1.24; for Ala/Ala vs. Val/Val: OR = 1.22, 95% CI = 1.00-1.49; for dominant model: OR = 1.14, 95% CI = 1.03-1.26). In the subgroup analysis by ethnicity, statistically significant increased risks were found among Caucasians with Ala allele (for Val/Ala vs. Val/Val: OR = 1.12, 95% CI = 1.00-1.25; for dominant model: OR = 1.14, 95% CI = 1.02-1.26). However, no significant associations were found in Africans.
Conclusions: This meta-analysis suggests that the Ala allele of the MnSOD gene was a low-penetrance susceptible gene in PCA development, especially in Caucasians.