Replicative study of GWAS TP63C/T, TERTC/T, and SLC14A1C/T with susceptibility to bladder cancer in North Indians

Objective: Genome-wide association studies have confirmed association of TP63C/T rs710521, TERTC/T rs2736098, and SLC14A1C/T rs17674580 gene variants with susceptibility to bladder cancer (BC) in European and White population. However, the risk conferred for BC for above gene variants in North Indians is unknown. We therefore, studied the association of TP63C/T, TERTC/T, and SLC14A1C/T single nucleotide polymorphisms (SNPs) with a risk of BC susceptibility in North Indian cohort.

Material and methods: In histologically confirmed 225 BC cases and 240 healthy controls, 3 SNPs were genotyped by real-time polymerase chain reaction. To evaluate the SNP effects on BC susceptibility, odds ratio (OR) and CI 95% were calculated.

Results: In case of TP63C/T, the variant genotype (TT) showed significant reduced risk for BC (P = 0.045, OR = 0.53). Combining heterozygous and variant genotypes also demonstrated reduced risk for BC (P< 0.001, OR = 0.54). In case of TERTC/T, heterozygous genotype (CT) as well as variant genotype (TT) showed significant risk for BC susceptibility (P = 0.031, OR = 1.77 and P = 0.004, OR = 2.78, respectively) along with T allelic level (P<0.001, OR = 4.19). Furthermore, in case of SLC14A1C/T gene polymorphism, the variant genotype (TT) showed significant high risk for BC susceptibility (P = 0.006; OR = 3.01) along with variant T allelic level (P = 0.003, OR = 1.52). Interestingly, smoking was also found to modulate risks for BC in case of TERT and SLC14A1 variant genotype (TT). Further clinical confounding factor, namely, tumor grade/stage level of cases, supports the genotypic data with TERT and SLC14A1 showing a risk for BC susceptibility.

Conclusion: Our results suggested that polymorphism in TERTC/T and SLC14A1C/T confirmed high risk for BC in North Indian population. However, TP63C/T showed reduced risk of BC susceptibility. More replicate studies with large sample size and diverse ethnicity are required to validate these observations.