title: Circulating enterolactone and prostate cancer risk: a Nordic nested case-control study.
abstract: Enterolactone, a phytoestrogen belonging to the class of lignans, is produced by the intestinal microflora from precursors in plant foods and has been implicated in protection against cancer. We study the effect of enterolactone on the risk of a subsequent diagnosis of prostate cancer. We conducted a longitudinal, nested case-control study by linkage of 3 biobanks to the cancer registries in Finland, Norway and Sweden, respectively. Enterolactone concentrations were measured by time-resolved fluoroimmunoassay in serum from 794 men who had a diagnosis of prostate cancer at a mean follow-up time of 14.2 years after blood collection and among 2,550 control men matched within each cohort for age (+/-2 years), date of blood collection (+/-2 months) and county. The median enterolactone concentrations did not differ between case and control subjects in the full study group (8.4 nmol/L [25th-75th percentile = 4.5-15.0] vs. 8.5 nmol/L [25th-75th percentile = 4.3-15.9]), nor in the national groups. Odds ratios of prostate cancer risk estimated by conditional logistic regression for increasing concentrations of enterolactone in quartiles in the full study group were 1.00 (referent), 1.21 (95% confidence interval [CI] = 0.96-1.52), 1.16 (95% CI = 0.91-1.47) and 1.08 (95% CI = 0.83-1.39). The OR estimate for the highest vs. the lowest quartile of enterolactone in separate analyses of the Norwegian, Finnish and Swedish cohort was 1.21 (95% CI = 0.91-1.60), 1.02 (95% CI = 0.59-1.76) and 0.87 (95% CI = 0.45-1.67), respectively. No support for the hypothesis that high circulating enterolactone is protective against prostate cancer was found.
authors.affiliation: Department of Urology, Umeå University Hospital, Umeå, Sweden.
authors.forename: Pär
authors.initials: P
authors.lastname: Stattin
authors.forename: Herman
authors.initials: H
authors.lastname: Adlercreutz
authors.forename: Leena
authors.initials: L
authors.lastname: Tenkanen
authors.forename: Egil
authors.initials: E
authors.lastname: Jellum
authors.forename: Sonja
authors.initials: S
authors.lastname: Lumme
authors.forename: Göran
authors.initials: G
authors.lastname: Hallmans
authors.forename: Sverre
authors.initials: S
authors.lastname: Harvei
authors.forename: Lyly
authors.initials: L
authors.lastname: Teppo
authors.forename: Katariina
authors.initials: K
authors.lastname: Stumpf
authors.forename: Tapio
authors.initials: T
authors.lastname: Luostarinen
authors.forename: Matti
authors.initials: M
authors.lastname: Lehtinen
authors.forename: Joakim
authors.initials: J
authors.lastname: Dillner
authors.forename: Matti
authors.initials: M
authors.lastname: Hakama
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000097:blood*; D016022:Case-Control Studies; D015331:Cohort Studies; D004967:Estrogens / Q000097:blood; D005387:Finland / Q000453:epidemiology; D015200:Fluoroimmunoassay; D006801:Humans; D017705:Lignans / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000097:blood / Q000453:epidemiology*; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
chemical_list: D004967:Estrogens; D017705:Lignans; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone