Serum Retinol and Carotenoid Concentrations and Prostate Cancer Risk: Results from the Prostate Cancer Prevention Trial.
BACKGROUND
Findings from epidemiologic studies examining associations of serum retinol and carotenoids with prostate cancer risk have been inconsistent. This case-control study nested in the Prostate Cancer Prevention Trial evaluated associations of serum retinol and carotenoids with total, low-, and high-grade prostate cancer risk in a highly screened study population.


METHODS
We used logistic regression adjusting for age, family history of prostate cancer, race, body mass index, and serum cholesterol to estimate ORs and 95% confidence intervals (CI) of prostate cancer by quartiles of serum retinol and carotenoids, separately in the placebo (975 cases/1,009 frequency-matched controls) and finasteride (708 cases/743 frequency-matched controls) arms of the trial.


RESULTS
Serum retinol concentrations were associated with increased risk of total prostate cancer [OR (95% CI) comparing the highest quartile of serum retinol with the lowest: 1.30 (1.00-1.68)] and high-grade prostate cancer [OR (95% CI), 1.74 (1.14-2.68)] in the placebo arm of the trial only. Also in the placebo arm, there was a moderate positive association of α-carotene with risk of total prostate cancer [OR (95% CI), 1.32 (1.01-1.73)]. None of the other carotenoids was associated with prostate cancer risk in the placebo arm. No associations were observed for retinol and carotenoids in the finasteride arm.


CONCLUSIONS
In the placebo arm of this prospective study, high serum retinol and α-carotene concentrations were associated with increased risk of total and high-grade prostate cancers.


CONCLUSIONS
Men with higher levels of serum retinol and α-carotene may be at increased risk for prostate cancer.
Cancer Prevention Fellowship Program, Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland.
Sarah H
SH
Nash
SWOG Statistical Center, Fred Hutchinson Cancer Research Center, Seattle, Washington.
Cathee
C
Till
Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, Washington.
Xiaoling
X
Song
Department of Pathology, School of Medicine, University of Colorado Anschutz Medical Campus, Denver, Colorado.
M Scott
MS
Lucia
Prostate and Urologic Cancer Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland.
Howard L
HL
Parnes
Department of Urology, School of Medicine, University of Texas Health Science Center, San Antonio, Texas.
Ian M
IM
Thompson
Office of the Director, Moores Cancer Center, University of California at San Diego, San Diego, California.
Scott M
SM
Lippman
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland. Department of Urology, and the James Buchanan Brady Urological Institute, Johns Hopkins School of Medicine, Baltimore, Maryland. Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.
Elizabeth A
EA
Platz
Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, Washington. jschenk@fredhutch.org.
Jeannette
J
Schenk
D058891:5-alpha Reductase Inhibitors / Q000627:therapeutic use; D000368:Aged; D000975:Antioxidants / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood; D002338:Carotenoids / Q000097:blood*; D018120:Finasteride / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000097:blood* / Q000453:epidemiology / Q000517:prevention & control; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014801:Vitamin A / Q000097:blood* / Q000627:therapeutic use; D014815:Vitamins / Q000097:blood / Q000627:therapeutic use
D058891:5-alpha Reductase Inhibitors; D000975:Antioxidants; D014408:Biomarkers, Tumor; D014815:Vitamins; D014801:Vitamin A; D002338:Carotenoids; D018120:Finasteride