50-bp insertion/deletion polymorphism of the superoxide dismutase-1 is associated with bladder cancer risk in an Iranian population.

Bladder cancer (BC) is considered the sixth prevalent malignancy in men and the ninth leading cause of malignancy-related worldwide. Superoxide dismutase (SOD) is an antioxidant enzyme in the defense system against oxidative stress. Hence, we aimed to investigate whether the 50 bp Insertion/Deletion(Ins/Del) polymorphism of the SOD1 associated with the risk of BC. The study was conducted on 158 BC patients and 153 age-matched healthy subjects. Genomic DNA from all individuals was screened for the 50-bp SOD1 promoter deletion using PCR assay. Our results demonstrated an association between SOD1 Ins/Del (45% vs. 32%) genotype and risk of BC and this genotype elevated the susceptibility to BC (OR = 1.80, 95% CI: (1.10-2.90), P  = 0.01). In addition, the Del allele of the SOD1 variation was detected to be more prevalent in the BC patients with the frequency of 28% and 20% in cases and healthy groups, correspondingly (OR = 1.61, 95% CI: (1.10-2.36), P  = 0.01). It seems that SOD1 50-bp Ins/Del genotype, as well as Del, allele, is associated with an increased risk of BC in an Iranian population. However, further investigations in more diverse populations are necessary to assess the value of the novel biomarkers as a risk stratification biomarker for BC.