Fish consumption and prostate cancer risk and mortality in a Danish cohort study

Within the Danish 'Diet, Cancer and Health' cohort, we aimed to investigate the association between prediagnostic fish intake (total, lean, fatty) and (a) incidence of total and high-grade prostate cancer and (b) the risk of all-cause and prostate cancer-specific mortality among men with prostate cancer. Among 27 178 men, 1690 prostate cancer cases were identified through 2012. Of these, 1042 had a Gleason score of 7 or above and 498 had a Gleason score of 8 or above at the time of diagnosis; 364 died (n=228 from prostate cancer) during follow-up through 2013. Cox proportional hazard models were used for the statistical analyses. No association between any type of fish intake and risk of total prostate cancer or high-grade prostate cancer (Gleason score≥7 or ≥8) was found. For all-cause mortality, we found no association for any type of fish intake. For prostate cancer-specific mortality, only a higher intake of fatty fish was associated with a higher mortality [per daily 25 g increment in intake (mortality rate ratio=1.27; 95% confidence interval: 1.04-1.55; P=0.02)]. In conclusion, no strong association was found between fish consumption and the risk of or mortality from prostate cancer. Only a higher intake of fatty fish was associated with a higher risk of prostate cancer-specific mortality.