Dairy intake after prostate cancer diagnosis in relation to disease-specific and total mortality

Information regarding postdiagnostic dairy intake and prostate cancer survival is limited. We evaluated intake of total, high-fat and low-fat dairy after prostate cancer diagnosis in relation to disease-specific and total mortality. We included 926 men from the Physicians' Health Study diagnosed with non-metastatic prostate cancer between 1982 and 2000 who completed a diet questionnaire a median of 5 years after diagnosis and were followed thereafter for a median of 10 years to assess mortality. Cox proportional hazards regression was used to estimate associations between dairy intake and prostate cancer specific and all-cause mortality. During 8,903 person-years of follow-up, 333 men died, 56 due to prostate cancer. Men consuming ≥3 servings/day of total dairy products had a 76% higher risk of total mortality and a 141% higher risk of prostate cancer-specific mortality compared to men who consumed less than 1 dairy product/day (hazard ratio (HR) = 1.76, 95% confidence interval (CI): 1.21, 2.55, ptrend < 0.001 for total mortality; HR = 2.41, 95% CI: 0.96, 6.02, ptrend = 0.04 for prostate cancer-specific mortality). The association between high-fat dairy and mortality risk appeared to be stronger than that of low-fat dairy, but the difference between them was not statistically significant (p for difference = 0.57 for prostate cancer-specific mortality and 0.56 for total mortality). Among men without metastases when diagnosed, higher intake of dairy foods after prostate cancer diagnosis may be associated with increased prostate cancer-specific and all-cause mortality.