Association of coffee intake with risk of all-cause and colorectal cancer-specific mortality among individuals with colorectal cancer in the Multiethnic Cohort Study.

PURPOSE: Coffee may influence colorectal cancer (CRC) survival, but prior studies had limited generalizability. METHODS: We analyzed 1,098 participants from the Multiethnic Cohort study diagnosed with CRC between 1993-2008 who completed a food frequency questionnaire after diagnosis and were followed through 2019. Multivariable Cox proportional hazards regression models were used to examine coffee (total, caffeinated, decaffeinated) in relation to all-cause and CRC-specific mortality. Secondarily, we examined caffeine intake and explored associations by race and ethnicity. RESULTS: Overall, coffee intake was not associated with risk of mortality. However, decaffeinated coffee was associated with lower risk of all-cause mortality (HR ≥1 vs. 0 cups/day: 0.71; 95% CI [0.55 - 0.91]). Additionally, associations were observed between total and caffeinated coffee in relation to all-cause mortality among Native Hawaiian participants (HR per 1 cup/day: 0.62 [0.41 - 0.94] and 0.55 [0.31 - 0.97], respectively); and with CRC-specific mortality among White participants (HR per 1 cup/day: 0.48 [0.25-0.94] and 0.45 [0.23 - 0.90], respectively). In the total cohort, caffeine intake was associated with 22% lower risk of all-cause mortality (HR 4th quartile vs. 1st quartile: 0.78 [0.62-0.99]) and 52% lower risk of CRC-specific mortality (HR 0.48 [0.27-0.87]). CONCLUSIONS: Overall, coffee intake after CRC diagnosis was not associated with all-cause or CRC-specific mortality. Decaffeinated coffee was associated with lower risk of all-cause mortality, and caffeine was associated with lower risk of all-cause and CRC-specific mortality.