A Summary of the Prostate Cancer Prevention Trials With a Focus on the Role of Vitamin E

2012 ◽  
Vol 25 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Fadi Abu-Shahin ◽  
William Stone ◽  
Victoria Ramsauer ◽  
Koyamangalath Krishnan
2005 ◽  
Vol 23 (32) ◽  
pp. 8161-8164 ◽  
Author(s):  
Ian M. Thompson ◽  
Catherine M. Tangen ◽  
Eric A. Klein ◽  
Scott M. Lippman

One randomized, prospective clinical trial for chemoprevention of prostate cancer has been completed, and two additional trials are ongoing. The investment, time, and effort for these trials are substantial. We reviewed the outcomes of these trials to address the value of the investment. The outcomes of the Prostate Cancer Prevention Trial (testing finasteride) and the design of the Selenium and Vitamin E Cancer Prevention Trial (SELECT; testing vitamin E and selenium) trial as well as the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial (testing dutasteride) were reviewed. From a public health standpoint, there is tremendous potential for benefit from large-scale cancer prevention trials. Because of the volume of data that are collected, potential discoveries related to the biology of the disease are substantial. Translational scientific efforts are direct outgrowths of these studies. Prospective, randomized chemoprevention trials for prostate and other cancers are expensive and require long periods of time to conduct, yet the rewards are on a par with the investment.


2022 ◽  
Vol 11 ◽  
Author(s):  
Zhihong Gong ◽  
Mary E. Platek ◽  
Cathee Till ◽  
Phyllis J. Goodman ◽  
Catherine M. Tangen ◽  
...  

Study of polymorphisms in genes related to the generation and removal of oxidative stress and repair of oxidative DNA damage will lead to new insights into the genetic basis of prostate cancer. In the Prostate Cancer Prevention Trial (PCPT), a double-blind, randomized controlled trial testing finasteride versus placebo for prostate cancer prevention, we intend to investigate the role of oxidative stress/DNA repair mechanisms in prostate cancer etiology and whether these polymorphisms modify prostate cancer risk by interacting with antioxidant status in both placebo and finasteride arms. We evaluated associations of selected candidate polymorphisms in genes in these pathways, and interactions with pre-diagnostic serum antioxidants, and the risk of prostate cancer among 1,598 cases and 1,706 frequency-matched controls enrolled in the PCPT. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable-adjusted logistic regression models. While there were no statistically significant associations observed in the placebo arm, several SNPs were associated with prostate cancer in the finasteride arm. Specifically, APEX1-rs1760944 was associated with increased risk of total prostate cancer (per minor allele: p-trend=0.04). OGG1-rs1052133 was positively (CG/GG vs. CC: OR=1.32, 95% CI: 1.01-1.73) and NOS3-rs1799983 was inversely (per minor allele: p-trend=0.04) associated with risk of low-grade prostate cancer. LIG3-rs1052536 and XRCC1-rs25489 were suggestively associated with reduced risk of high-grade prostate cancer (per minor allele: both p-trend=0.04). In the placebo arm, significant associations were observed among men with higher serum lycopene for APEX1-rs1760944 and NQO1-rs1800566, or higher serum β-cryptoxanthin for ERCC4-rs1800067. In the finasteride arm, stronger associations were observed among men with lower serum lycopene for NOS3-rs1799983, higher serum α-carotene, β-carotene, and β-cryptoxanthin for LIG3-rs1052536, or lower serum retinol for SOD2-rs1799725. These results suggest that germline variations in oxidative stress and DNA repair pathways may contribute to prostate carcinogenesis and that these associations may differ by intraprostatic sex steroid hormone status and be further modified by antioxidant status. Findings provide insights into the complex role of gene, gene-antioxidant and -finasteride interactions in prostate cancer etiology, and thus may lead to the development of preventative strategies.


2001 ◽  
Vol 39 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Marian L. Neuhouser ◽  
Alan R. Kristal ◽  
Ruth E. Patterson ◽  
Phyllis J. Goodman ◽  
Ian M. Thompson

2016 ◽  
Vol 34 (36) ◽  
pp. 4338-4344 ◽  
Author(s):  
Catherine M. Tangen ◽  
Phyllis J. Goodman ◽  
Cathee Till ◽  
Jeannette M. Schenk ◽  
M. Scott Lucia ◽  
...  

Purpose To identify factors related to who undergoes a prostate biopsy in a screened population and to estimate the impact of biopsy verification on risk factor–prostate cancer associations. Patients and Methods Men who were screened regularly from the placebo arms of two large prostate cancer prevention trials (Prostate Cancer Prevention Trial [PCPT] and Selenium and Vitamin E Cancer Prevention Trial [SELECT]) were examined to define incident prostate cancer cohorts. Because PCPT had an end-of-study biopsy, prostate cancer cases were categorized by a preceding prostate-specific antigen/digital rectal examination prompt (yes/no) and noncases by biopsy-proven negative status (yes v no). We estimated the association of risk factors (age, ethnicity, family history, body mass index, medication use) with prostate cancer and quantified differences in risk associations across cohorts. Results Men 60 to 69 years of age, those with benign prostatic hyperplasia, and those with a family history of prostate cancer were more likely, and those with a higher body mass index (≥ 25), diabetes, or a smoking history were less likely, to undergo biopsy, adjusting for age and longitudinal prostate-specific antigen and digital rectal examination. Medication use, education, and marital status also influenced who underwent biopsy. Some risk factor estimates for prostate cancer varied substantially across cohorts. Black ( v other ethnicities) had odds ratios (ORs) that varied from 1.20 for SELECT (community screening standards, epidemiologic-like cohort) to 1.83 for PCPT (end-of-study biopsy supplemented with imputed end points). Statin use in SELECT provided an OR of 0.65 and statin use in in PCPT provided an OR of 0.99, a relative difference of 34%. Conclusion Among screened men enrolled in prostate cancer prevention trials, differences in risk factor estimates for prostate cancer likely underestimate the magnitude of bias found in other cohorts with varying screening and biopsy recommendations and acceptance. Risk factors for prostate cancer derived from epidemiologic studies not only may be erroneous but may lead to misdirected research efforts.


2011 ◽  
Vol 11 ◽  
pp. 742-748 ◽  
Author(s):  
Barbara Ercole ◽  
Dipen J. Parekh

Chemoprevention for prostate cancer (PCa) continues to generate interest from both physicians and the patient population. The goal of chemoprevention is to stop the malignant transformation of prostate cells into cancer. Multiple studies on different substances ranging from supplements to medical therapy have been undertaken. Thus far, only the studies on 5α-reductase inhibitors (the Prostate Cancer Prevention Trial [PCPT] and Reduction by Dutasteride of Prostate Cancer Events [REDUCE] trial) have demonstrated a reduction in the risk of PCa, while results from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) concluded no decreased risk for PCa with selenium or vitamin E.


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