Serum lycopene, other carotenoids, and prostate cancer risk: a nested case-control study in the prostate, lung, colorectal, and ovarian cancer screening trial.
BACKGROUND
Reports from several studies have suggested that carotenoids, and in particular lycopene, could be prostate cancer-preventive agents. This has stimulated extensive laboratory and clinical research, as well as much commercial and public enthusiasm. However, the epidemiologic evidence remains inconclusive.


METHODS
We investigated the association between prediagnostic serum carotenoids (lycopene, alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, and zeaxanthin) and risk of prostate cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, a multicenter study designed to examine methods of early detection and risk factors for cancer. The study included 692 incident prostate cancer cases, diagnosed 1 to 8 years after study entry, including 270 aggressive cases, with regional or distant stage (n = 90) or Gleason score >or=7 (n = 235), and 844 randomly selected, matched controls. As study participants were selected from those who were assigned to annual standardized screening for prostate cancer, results are unlikely to be biased by differential screening, a circumstance that is difficult to attain under non-trial conditions.


RESULTS
No association was observed between serum lycopene and total prostate cancer [odds ratios (OR), 1.14; 95% confidence intervals (95% CI), 0.82-1.58 for highest versus lowest quintile; P for trend, 0.28] or aggressive prostate cancer (OR, 0.99; 95% CI, 0.62-1.57 for highest versus lowest quintile; P for trend, 0.433). beta-Carotene was associated with an increased risk of aggressive prostate cancer (OR, 1.67; 95% CI, 1.03-2.72 for highest versus lowest quintile; P for trend, 0.13); in particular, regional or distant stage disease (OR, 3.16; 95% CI, 1.37-7.31 for highest versus lowest quintile; P for trend, 0.02); other carotenoids were not associated with risk.


CONCLUSIONS
In this large prospective study, high serum beta-carotene concentrations were associated with increased risk for aggressive, clinically relevant prostate cancer. Lycopene and other carotenoids were unrelated to prostate cancer. Consistent with other recent publications, these results suggest that lycopene or tomato-based regimens will not be effective for prostate cancer prevention.
Peters
Ulrike
U
Cancer Prevention Program, Fred Hutchinson Cancer Research Center, P.O. Box 19024, 1100 Fairview Avenue North M4-B402, Seattle, WA 98109-1024, USA. upeters@fhcrc.org
Leitzmann
Michael F
MF
Chatterjee
Nilanjan
N
Wang
Yinghui
Y
Albanes
Demetrius
D
Gelmann
Edward P
EP
Friesen
Marlin D
MD
Riboli
Elio
E
Hayes
Richard B
RB
D000368:Aged; D016588:Anticarcinogenic Agents / Q000097:blood*; D002338:Carotenoids / Q000097:blood*; D016022:Case-Control Studies; D016001:Confidence Intervals; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D000077276:Lycopene; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000517:prevention & control*; D018570:Risk Assessment; D011795:Surveys and Questionnaires; D019207:beta Carotene / Q000009:adverse effects / Q000097:blood
D016588:Anticarcinogenic Agents; D019207:beta Carotene; D002338:Carotenoids; D000077276:Lycopene