Diet quality, common genetic polymorphisms, and bladder cancer risk in a New England population-based study

Purpose We examined the interaction between common genetic bladder cancer variants, diet quality, and bladder cancer risk in a population-based case–control study conducted in New England. Methods At the time of enrollment, 806 bladder cancer cases and 974 controls provided a DNA sample and completed a diet history questionnaire. Diet quality was assessed using the 2010 Alternate Healthy Eating Index (AHEI-2010) score. Single nucleotide polymorphisms (SNPs) reported in genome-wide association studies to be associated with bladder cancer risk were combined into a polygenic risk score and also examined individually for interaction with the AHEI-2010. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression. Results A 1-standard deviation increase in polygenic risk score was associated with higher bladder cancer risk (OR, 1.34; 95% CI 1.21–1.49). Adherence to the AHEI-2010 was not associated with bladder cancer risk (OR, 0.99; 95% CI 0.98–1.00) and the polygenic risk score did not appear to modify the association between the AHEI-2010 and bladder cancer risk. In single-SNP analyses, rs8102137 (bladder cancer risk allele, C) modified the association between the AHEI-2010 total score and bladder cancer risk, with the strongest evidence for the AHEI-2010 long chain fat guideline (OR for TT, 0.92; 95% CI 0.87–0.98; OR for CT, 1.02; 95% CI 0.96–1.08; OR for CC, 1.03; 95% CI 0.93–1.14; p for interaction, 0.02). Conclusions In conclusion, rs8102137 near the cyclin E1 gene ( CCNE1 ) may be involved in gene–diet interactions for bladder cancer risk.