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.