Prediagnostic enterolactone concentrations and mortality among Danish men diagnosed with prostate cancer

BACKGROUND/OBJECTIVES: Evidence on the role of diet in relation to prostate cancer progression is sparse. Foods rich in lignans have shown beneficial effects on prostate cancer progression in both animal studies and small human intervention studies, including beneficial effects on prostate-specific antigen levels and tumour growth. The lignan metabolite, enterolactone, has further shown to slow prostate cancer cell growth in vitro. The aim was to investigate the association between prediagnostic enterolactone concentrations and mortality among men with prostate cancer. SSUBLJECTS/METHODS: Prediagnostic plasma concentrations of enterolactone from 1390 men diagnosed with prostate cancer from the Danish Diet, Cancer and Health cohort were related to all-cause or prostate cancer-specific death, using Cox proportional hazards models with follow-up time (from the date of diagnose until the date of death, emigration or end of follow-up by December 2013) as the underlying time axis. RESULTS: The hazard ratios for enterolactone concentrations assessed linearly by 20 nmol/l increments was 0.95 (0.90, 1.02) for all-cause mortality and 0.98 (0.92, 1.05) for prostate cancer-specific mortality. Categorisation of enterolactone concentrations into quartiles did not reveal a different pattern. No effect modifications by smoking, body mass index or sport were observed, and the associations did not differ by prostate cancer aggressiveness. CONCLUSIONS: We found no association between enterolactone concentrations and mortality among men diagnosed with prostate cancer.