Genetic variations in regulator of G‐protein signaling (RGS) confer risk of bladder cancer

BACKGROUND:

Alterations in the regulator of G‐protein signaling (RGS) pathway have been implicated in several cancers; therefore, the authors investigated the role of such alterations in overall bladder cancer risk, recurrence, progression, and survival.

METHODS:

In this case‐control series, 803 patients with bladder cancer were frequency‐matched with a control cohort of 803 healthy individuals. Ninety‐five single‐nucleotide polymorphisms (SNPs) in 17 RGS genes were investigated for an association with overall bladder cancer risk, recurrence, and progression in patients who had nonmuscle‐invasive bladder cancer (NMIBC) and for an association with death in patients who had muscle‐invasive bladder cancer (MIBC). Cumulative effects and classification and regression tree analyses were performed for SNPs that were associated with overall bladder cancer risk. Kaplan‐Meier plots were created to evaluate differences in the survival of patients with MIBC.

RESULTS:

Reference SNP 10759 (rs10759) on the RGS4 gene demonstrated the greatest association with overall bladder cancer risk, conferring a 0.77‐fold reduced risk with an increasing number of variant alleles (P < .001). A cumulative effects analysis that included all 5 significant SNPs demonstrated an increasing risk with the number of unfavorable genotypes (odds ratio, 4.13; 95% confidence interval, 2.14‐7.98). In patients with NMIBC, 11 SNPs were identified that had an association with disease recurrence, and 13 SNPs were associated with disease progression. Of the 10 SNPs that were associated with death in patients with MIBC, rs2344673 in an additive model was the most significant and was associated with a decreased median survival of 13.3 months compared with 81.9 months in individuals without a variant allele.

CONCLUSIONS:

Genetic variations in the RGS pathway were associated with the overall risk of bladder cancer, recurrence, and progression in patients with NMIBC and with the risk of death in patients with MIBC. Cancer 2013. © 2013 American Cancer Society.