Lycopene and prostate cancer risk. Methodological considerations in the epidemiologic literature

2002 ◽  
Vol 74 (8) ◽  
pp. 1427-1434 ◽  
Author(s):  
Edward Giovannucci

Prostate cancer is the most common cancer in U.S. males. Among potentially beneficial natural compounds is lycopene, which is derived largely from tomato-based products. Recent epidemiologic studies have suggested a potential benefit of this carotenoid against risk of prostate cancer, but not all of the studies have been supportive. The largest prospective dietary study, the Health Professionals Follow-Up Study (HPFS), had found that 2-4 servings of tomato sauce per week were associated with about a 35 % risk reduction of total prostate cancer and a 50 % reduction of advanced prostate cancer in follow-up from 1986 to 1992. Tomato sauce was by far the strongest predictor of plasma lycopene levels in this study. In the largest plasma-based study, high lycopene levels were associated with similar risk reductions for total and advanced prostate cancer. Results from other studies, mostly dietary case-control studies, have been mixed. The reasons for these inconsistencies are unclear. Because lycopene may come from a number of sources, and the bioavailability of lycopene may vary profoundly across these sources, dietary questionnaires are likely to vary markedly in their utility to estimate true variation in body lycopene stores across individuals. With further follow-up in the HPFS, we addressed some possibilities for apparently conflicting results. We confirmed our initial findings with the independent 1992­1998 follow-up period. Our results also indicated various factors may contribute to some of the inconsistencies, including insufficient sample size, low intake of lycopene, failure to account for bioavailability, reliance on a single dietary assessment, and heterogeneity of prostate cancer.

2002 ◽  
Vol 227 (10) ◽  
pp. 852-859 ◽  
Author(s):  
Edward Giovannucci

Prostate cancer is the most common cancer in American men. Preventable measures for this malignancy are not well established. Among potentially beneficial natural compounds is the carotenoid lycopene, which is derived largely from tomato-based products. Recent epidemiologic studies have suggested a potential benefit of this carotenoid against the risk of prostate cancer, particularly the more lethal forms of this cancer. Five studies support a 30% to 40% reduction in risk associated with high tomato or lycopene consumption, three are consistent with a 30% reduction in risk, but the results were not statistically significant, and seven were not supportive of an association. The largest relevant dietary study, a prospective study in male health professionals found that consumption of two to four servings of tomato sauce per week was associated with about a 35% risk reduction of total prostate cancer and a 50% reduction of advanced (extraprostatic) prostate cancer. Tomato sauce was by far the strongest predictor of plasma lycopene levels in this study. In the largest plasma-based study, very similar risk reductions were observed for total and advanced prostate cancer for the highest versus lowest quintile of lycopene. Other studies, mostly dietary case-control studies, have not been as supportive of this hypothesis. The reasons for these inconsistencies are unclear, but in three of the seven null studies, tomato consumption or serum lycopene level may have been too low to observe an effect. Because the concentration and bioavailability of lycopene vary greatly across the various food items, dietary questionnaires vary markedly in their usefulness of estimating the true variation in tissue lycopene concentrations across individuals. To optimize the interpretation of future findings, the usefulness of the questionnaire to measure lycopene levels in a population should be directly assessed. Although not definitive, the available data suggest that increased consumption of tomatoes and tomato-based products may be prudent.


Metabolites ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 99 ◽  
Author(s):  
Barbra A. Dickerman ◽  
Ericka M. Ebot ◽  
Brian C. Healy ◽  
Kathryn M. Wilson ◽  
A. Heather Eliassen ◽  
...  

Obesity is associated with a higher risk of advanced prostate cancer, but men with the same body mass index (BMI) may differ in their underlying metabolic health. Using metabolomics data from nested case-control studies in the Health Professionals Follow-Up Study, we calculated Pearson correlations between 165 circulating metabolites and three adiposity measures (BMI, waist circumference, and derived fat mass from a validated prediction equation) to identify adiposity-associated metabolites. We used Lasso to further select metabolites for prediction models of adiposity measures, which we used to calculate metabolic scores representing metabolic obesity. In an independent set of 212 advanced prostate cancer cases (T3b/T4/N1/M1 or lethal during follow-up) and 212 controls, we used logistic regression to evaluate the associations between adiposity measures and metabolic scores with risk of advanced disease. All adiposity measures were associated with higher blood levels of carnitines (Pearson r range, 0.16 to 0.18) and lower levels of glutamine (r = −0.19) and glycine (r, −0.29 to −0.20), in addition to alterations in various lipids. No adiposity measure or metabolic score was associated with risk of advanced prostate cancer (e.g., odds ratio for a 5 kg/m2 increase in BMI 0.96 (95% CI: 0.73, 1.27) and BMI metabolic score 1.18 (95% CI: 0.57, 2.48)). BMI, waist circumference, and derived fat mass were associated with a broad range of metabolic alterations. Neither adiposity nor metabolic scores were associated with risk of advanced prostate cancer.


2009 ◽  
Vol 181 (4S) ◽  
pp. 166-167
Author(s):  
Lauren P Wallner ◽  
Michaela McGree ◽  
Debra J Jacobson ◽  
Jennifer L St. Sauver ◽  
Steven J Jacobsen ◽  
...  

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e46982 ◽  
Author(s):  
Bingbing Wei ◽  
Zhuoqun Xu ◽  
You Zhou ◽  
Jun Ruan ◽  
Huan Cheng ◽  
...  

2010 ◽  
Vol 28 (18_suppl) ◽  
pp. CRA4504-CRA4504 ◽  
Author(s):  
P. R. Warde ◽  
M. D. Mason ◽  
M. R. Sydes ◽  
M. K. Gospodarowicz ◽  
G. P. Swanson ◽  
...  

CRA4504 Background: The impact of radiotherapy on overall survival (OS) in men with locally advanced CaP is unclear. The SPCG-7 trial recently showed a benefit to RT for CaP specific mortality. Our primary objective was to assess the effect of RT on OS when added to lifelong ADT in men with locally advanced CaP. Methods: Patients with T3/T4 (1057) or T2, PSA > 40 μ g/l (119) or T2 PSA > 20 μ g/l and Gleason ≥ 8 (25) and N0 /NX, M0 prostate adenocarcinoma were randomized to lifelong ADT (bilateral orchiectomy or LHRH agonist) with or without RT (65-69 Gy to prostate ± seminal vesicles with or without 45Gy to pelvic nodes). The primary endpoint was OS and secondary endpoints included disease specific survival (DSS), time to disease progression and quality of life. Results: 1205 patients were randomized from 1995 to 2005, 602 to ADT and 603 to ADT+RT (well balanced with respect to baseline characteristics). A protocol specified second interim analysis on OS was performed in Aug 2009 (data cut-off Dec 31 2008). The DSMC recommended release of the results to the Trial Committee for publication. The median follow-up is 6.0 years and 320 patients have died (175 ADT and 145 ADT+RT). 10% of patients had no follow-up data beyond 2006. The addition of RT to ADT significantly reduced the risk of death (hazard ratio [HR] 0.77, 95% CI 0.61-0.98, p=0.033). 140 patients died of disease and/or treatment (89 on ADT and 51 on ADT+RT) The disease specific survival HR was 0.57 (95% CI 0.41-0.81, p=0.001) favoring ADT+RT. The 10 year cumulative disease specific death rates were estimated at 15% with ADT+ RT and 23% with ADT alone. Grade ≥2 late GI toxicity rates were similar in both arms (proctitis, 1.3% ADT alone, 1.8% ADT+RT). Conclusions: The trial results indicate a substantial overall survival and disease specific survival benefit for the combined modality approach (ADT+RT) in the management of patients with locally advanced prostate cancer with no significant increase in late treatment toxicity. In view of this data combined modality therapy (ADT+RT) should be the standard treatment approach for these patients. Supported by NCI-US Grant #5U10CA077202-12, CCSRI Grant #15469. No significant financial relationships to disclose.


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