Coffee Intake, Caffeine Metabolism Genotype, and Survival Among Men with Prostate Cancer

Abstract

BackgroundCoffee intake may lower prostate cancer risk and progression, but postdiagnosis outcomes by caffeine metabolism genotype are not well characterized. ObjectiveTo evaluate associations between coffee intake, caffeine metabolism genotype, and survival in a large, multicenter study of men with prostate cancer. Design, setting, and participantsData from The PRACTICAL Consortium database for 5727 men with prostate cancer from seven US, Australian, and European studies were included. The cases included had data available for the CYP1A2 −163C>A rs762551 single-nucleotide variant associated with caffeine metabolism, coffee intake, and >6 mo of follow-up. Outcome measurements and statistical analysisMultivariable-adjusted Cox proportional hazards models across pooled patient-level data were used to compare the effect of coffee intake (categorized as low [reference], high, or none/very low) in relation to overall survival (OS) and prostate cancer–specific survival (PCSS), with stratified analyses conducted by clinical disease risk and genotype. Results and limitationsHigh coffee intake appeared to be associated with longer PCSS (hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.68–1.08; p = 0.18) and OS (HR 0.90, 95% CI 0.77–1.07; p = 0.24), although results were not statistically significant. In the group with clinically localized disease, high coffee intake was associated with longer PCSS (HR 0.66, 95% CI 0.44–0.98; p = 0.040), with comparable results for the group with advanced disease (HR 0.92, 95% CI 0.69–1.23; p = 0.6). High coffee intake was associated with longer PCSS among men with the CYP1A2 AA (HR 0.67, 95% CI 0.49–0.93; p = 0.017) but not the AC/CC genotype (p = 0.8); an interaction was detected (p = 0.042). No associations with OS were observed in subgroup analyses (p > 0.05). Limitations include the nominal statistical significance and residual confounding. ConclusionsCoffee intake was associated with longer PCSS among men with a CYP1A2 −163AA (*1F/*1F) genotype, a finding that will require further replication. Patient summaryIt is likely that coffee intake is associated with longer prostate cancer–specific survival in certain groups, but more research is needed to fully understand which men may benefit and why.