Coffee and tea consumption in relation to prostate cancer prognosis.

BACKGROUND: Bioactive compounds found in coffee and tea may delay the progression of prostate cancer. METHODS: We investigated associations of pre-diagnostic coffee and tea consumption with risk of prostate cancer recurrence/progression. Study participants were men diagnosed with prostate cancer in 2002-2005 in King County, Washington, USA. We assessed the usual pattern of coffee and tea consumption two years before diagnosis date. Prostate cancer-specific outcome events were identified using a detailed follow-up survey. Multivariable Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs). RESULTS: The analysis of coffee intake in relation to prostate cancer recurrence/progression included 630 patients with a median follow-up of 6.4 years, during which 140 prostate cancer recurrence/progression events were recorded. Approximately 61 % of patients consumed at least one cup of coffee per day. Coffee consumption was associated with a reduced risk of prostate cancer recurrence/progression; the adjusted HR for ≥4 cups/day versus ≤1 cup/week was 0.41 (95 % CI: 0.20, 0.81; p for trend = 0.01). Approximately 14 % of patients consumed one or more cups of tea per day, and tea consumption was unrelated to prostate cancer recurrence/progression. CONCLUSION: Results indicate that higher pre-diagnostic coffee consumption is associated with a lower risk of prostate cancer recurrence/progression. This finding will require replication in larger studies.