Differential Biopsy Patterns Influence Associations between Multivitamin Use and Prostate Cancer Risk in the Selenium and Vitamin E Cancer Prevention Trial.

BACKGROUND: Multivitamin (MVI) use is a common health behavior but there is conflicting evidence from prospective studies about whether this behavior increases or decreases prostate cancer risk. METHODS: Associations of MVI use and prostate cancer risk were evaluated using data from the Selenium and Vitamin E Cancer Prevention Trial (SELECT). Cox proportional hazards models estimated associations of MVI use with risk of total, low-, and high-grade prostate cancer. Longitudinal data were used to evaluate screening and biopsy patterns. To account for differential biopsy patterns, the probability of prostate cancer was estimated for men with a positive screening value but no biopsy. Incidence density ratios were used to approximate HRs, and associations of MVI use with predicted prostate cancer risk were compared with observed. RESULTS: Analyses of data from observed biopsies suggest a respective 19% (95% confidence interval, 10%-28%) and 21% (12%-31%) higher risk of high-grade prostate cancer for current and long-term MVI use, compared with no use. Current and long-term MVI use was associated with a shorter time to first on-study biopsy, indicating the potential for detection bias. After accounting for differential acceptance of biopsy, associations of MVI use with prostate cancer were attenuated and not statistically significant. CONCLUSIONS: In SELECT, biopsy acceptance patterns differed by MVI use. Estimates of associations of MVI use with prostate cancer risk based on observed biopsy data may be biased by differential acceptance of biopsy. IMPACT: Differential biopsy ascertainment may impact associations of risk factors and prostate cancer. Detailed screening and biopsy data can be used to analytically minimize such bias.

Effects of yoga in men with prostate cancer on quality of life and immune response: a pilot randomized controlled trial.

BACKGROUND: Diagnosis and treatment of prostate cancer is associated with anxiety, fear, and depression in up to one-third of men. Yoga improves health-related quality of life (QoL) in patients with several types of cancer, but evidence of its efficacy in enhancing QoL is lacking in prostate cancer. METHODS: In this randomized controlled study, 29 men newly diagnosed with localized prostate cancer were randomized to yoga for 6 weeks (n = 14) or standard-of-care (n = 15) before radical prostatectomy. The primary outcome was self-reported QoL, assessed by the Expanded Prostate Index Composite (EPIC), Functional Assessment of Cancer Therapy-Prostate (FACT-P), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Functional Assessment of Cancer Therapy-General (FACT-G) at baseline, preoperatively, and 6 weeks postoperatively. Secondary outcomes were changes in immune cell status and cytokine levels with yoga. RESULTS: The greatest benefit of yoga on QoL was seen in EPIC-sexual (mean difference, 8.5 points), FACIT-F (6.3 points), FACT-Functional wellbeing (8.6 points), FACT-physical wellbeing (5.5 points), and FACT-Social wellbeing (14.6 points). The yoga group showed increased numbers of circulating CD4+ and CD8+ T-cells, more production of interferon-gamma by natural killer cells, and increased Fc receptor III expression in natural killer cells. The yoga group also showed decreased numbers of regulatory T-cells, myeloid-derived suppressor cells, indicating antitumor activity, and reduction in inflammatory cytokine levels (granulocyte colony-stimulating factor [0.55 (0.05-1.05), p = 0.03], monocyte chemoattractant protein [0.22 (0.01-0.43), p = 0.04], and FMS-like tyrosine kinase-3 ligand [0.91 (-0.01, 1.82), p = 0.053]. CONCLUSIONS: Perioperative yoga exercise improved QoL, promoted an immune response, and attenuated inflammation in men with prostate cancer. Yoga is feasible in this setting and has benefits that require further investigation. TRIAL REGISTRATION: clinicaltrials.org (NCT02620033).

Association of Serum Carotenoids and Retinoids with Intraprostatic Inflammation in Men without Prostate Cancer or Clinical Indication for Biopsy in the Placebo Arm of the Prostate Cancer Prevention Trial.

Non-supplemental carotenoids and retinol may potentiate antioxidant and anti-inflammatory mechanisms. Chronic intraprostatic inflammation is linked to prostate carcinogenesis. We investigated the association of circulating carotenoids and retinol with intraprostatic inflammation in benign tissue. We included 235 men from the Prostate Cancer Prevention Trial placebo arm who had a negative end-of-study biopsy, most (92.8%) done without clinical indication. α-carotene, ß-carotene, ß-cryptoxanthin, lycopene, and retinol were assessed by high-performance liquid chromatography using pooled year 1 and 4 serum. Presence and extent of intraprostatic inflammation in benign tissue was assessed in 3 (of 6-10) biopsy cores. Logistic (any core with inflammation vs none) and polytomous logistic (some or all cores with inflammation vs none) regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) of intraprostatic inflammation by concentration tertile adjusting for age, race, prostate cancer family history, and serum cholesterol. None of the carotenoids or retinol was associated with intraprostatic inflammation, except ß-cryptoxanthin, which appeared to be positively associated with any core with inflammation [vs none, T2: OR (95% CI) = 2.67 (1.19, 5.99); T3: 1.80 (0.84, 3.82), P-trend = 0.12]. These findings suggest that common circulating carotenoids and retinol are not useful dietary intervention targets for preventing prostate cancer via modulating intraprostatic inflammation.

Colorectal Adenomas in Participants of the SELECT Randomized Trial of Selenium and Vitamin E for Prostate Cancer Prevention.

Selenium and vitamin E micronutrients have been advocated for the prevention of colorectal cancer. Colorectal adenoma occurrence was used as a surrogate for colorectal cancer in an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT) for prostate cancer prevention. The primary objective was to measure the effect of selenium (as selenomethionine) on colorectal adenomas occurrence, with the effect of vitamin E (as α-tocopherol) supplementation on colorectal adenoma occurrence considered as a secondary objective. Participants who underwent lower endoscopy while in SELECT were identified from a subgroup of the 35,533 men randomized in the trial. Adenoma occurrence was ascertained from the endoscopy and pathology reports for these procedures. Relative Risk (RR) estimates and 95% confidence intervals (CI) of adenoma occurrence were generated comparing those randomized to selenium versus placebo and to vitamin E versus placebo based on the full factorial design. Evaluable endoscopy information was obtained for 6,546 participants, of whom 2,286 had 1+ adenomas. Apart from 21 flexible sigmoidoscopies, all the procedures yielding adenomas were colonoscopies. Adenomas occurred in 34.2% and 35.7%, respectively, of participants whose intervention included or did not include selenium. Compared with placebo, the RR for adenoma occurrence in participants randomized to selenium was 0.96 (95% CI, 0.90-1.02; P = 0.194). Vitamin E did not affect adenoma occurrence compared with placebo (RR = 1.03; 95% CI, 0.96-1.10; P = 0.38). Neither selenium nor vitamin E supplementation can be recommended for colorectal adenoma prevention. Cancer Prev Res; 10(1); 45-54. ©2016 AACR.

Biases in Recommendations for and Acceptance of Prostate Biopsy Significantly Affect Assessment of Prostate Cancer Risk Factors: Results From Two Large Randomized Clinical Trials.

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.

Selenium- or Vitamin E-Related Gene Variants, Interaction with Supplementation, and Risk of High-Grade Prostate Cancer in SELECT.

BACKGROUND: Epidemiologic studies and secondary analyses of randomized trials supported the hypothesis that selenium and vitamin E lower prostate cancer risk. However, the Selenium and Vitamin E Cancer Prevention Trial (SELECT) showed no benefit of either supplement. Genetic variants involved in selenium or vitamin E metabolism or transport may underlie the complex associations of selenium and vitamin E. METHODS: We undertook a case-cohort study of SELECT participants randomized to placebo, selenium, or vitamin E. The subcohort included 1,434 men; our primary outcome was high-grade prostate cancer (N = 278 cases, Gleason 7 or higher cancer). We used weighted Cox regression to examine the association between SNPs and high-grade prostate cancer risk. To assess effect modification, we created interaction terms between randomization arm and genotype and calculated log likelihood statistics. RESULTS: We noted statistically significant (P < 0.05) interactions between selenium assignment, SNPs in CAT, SOD2, PRDX6, SOD3, and TXNRD2, and high-grade prostate cancer risk. Statistically significant SNPs that modified the association of vitamin E assignment and high-grade prostate cancer included SEC14L2, SOD1, and TTPA In the placebo arm, several SNPs, hypothesized to interact with supplement assignment and risk of high-grade prostate cancer, were also directly associated with outcome. CONCLUSION: Variants in selenium and vitamin E metabolism/transport genes may influence risk of overall and high-grade prostate cancer, and may modify an individual man's response to vitamin E or selenium supplementation with regards to these risks. IMPACT: The effect of selenium or vitamin E supplementation on high-grade prostate cancer risk may vary by genotype. Cancer Epidemiol Biomarkers Prev; 25(7); 1050-8. ©2016 AACR.

Difference in Association of Obesity With Prostate Cancer Risk Between US African American and Non-Hispanic White Men in the Selenium and Vitamin E Cancer Prevention Trial (SELECT).

IMPORTANCE: African American men have the highest rates of prostate cancer incidence and mortality in the United States. Understanding underlying reasons for this disparity could identify preventive interventions important to African American men. OBJECTIVE: To determine whether the association of obesity with prostate cancer risk differs between African American and non-Hispanic white men and whether obesity modifies the excess risk associated with African American race. DESIGN, SETTING, AND PARTICIPANTS: Prospective study of 3398 African American and 22,673 non-Hispanic white men who participated in the Selenium and Vitamin E Cancer Prevention Trial (2001-2011) with present analyses completed in 2014. MAIN OUTCOMES AND MEASURES: Total, low-grade (Gleason score <7), and high-grade (Gleason score ≥7) prostate cancer incidence. RESULTS: With a median (interquartile range) follow-up of 5.6 (1.8) years, there were 270, 148, and 88 cases of total, low-, and high-grade prostate cancers among African American men and a corresponding 1453, 898, and 441 cases in non-Hispanic white men, respectively. Although not associated with risk among non-Hispanic white men, BMI was positively associated with an increase in risk among African American men (BMI, <25 vs ≥35: hazard ratio [HR], 1.49 [95% CI, 0.95, 2.34]; P for trend = .03). Consequently, the risk associated with African American race increased from 28% (HR, 1.28 [95% CI, 0.91-1.80]) among men with BMI less than 25 to 103% (HR, 2.03 [95% CI, 1.38-2.98]) among African American men with BMI at least 35 (P for trend = .03). Body mass index was inversely associated with low-grade prostate cancer risk within non-Hispanic white men (BMI, <25 vs ≥35: HR, 0.80 [95% CI, 0.58-1.09]; P for trend = .02) but positively associated with risk within African American men (BMI, <25 vs ≥35: HR, 2.22 [95% CI, 1.17-4.21]; P for trend = .05). Body mass index was positively associated with risk of high-grade prostate cancer in both non-Hispanic white men (BMI, <25 vs ≥35: HR, 1.33 [95% CI, 0.90-1.97]; P for trend = .01) and African American men, although the increase may be larger within African American men, albeit the racial interaction was not statistically significant (BMI, <25 vs ≥35: HR, 1.81 [95% CI, 0.79-4.11]; P for trend = .02). CONCLUSIONS AND RELEVANCE: Obesity is more strongly associated with increased prostate cancer risk among African American than non-Hispanic white men and reducing obesity among African American men could reduce the racial disparity in cancer incidence. Additional research is needed to elucidate the mechanisms underlying the differential effects of obesity in African American and non-Hispanic white men.

Association between Serum Phospholipid Fatty Acids and Intraprostatic Inflammation in the Placebo Arm of the Prostate Cancer Prevention Trial.

Inflammation may play an etiologic role in prostate cancer. Several dietary factors influence inflammation; studies have shown that long-chain n-3 polyunsaturated fatty acids are anti-inflammatory, whereas n-6 and trans fatty acids are proinflammatory. We evaluated whether serum phospholipid n-3, n-6, and trans fatty acids were associated with intraprostatic inflammation, separately in 191 prostate cancer cases and 247 controls from the placebo arm of the Prostate Cancer Prevention Trial (PCPT). Men without a prostate cancer diagnosis underwent prostate biopsy at trial end, and benign prostate tissue inflammation was evaluated in approximately three biopsy cores per man; this was expressed as no, some, or all cores with inflammation. In controls, serum eicosapentaenoic acid [OR of all cores with inflammation versus none (95% CI), 0.35 (0.14-0.89)] and docosahexaenoic acid [OR (95% CI), 0.42 (0.17-1.02)] were inversely associated with, whereas linoleic acid [OR (95% CI), 3.85 (1.41-10.55)] was positively associated with intraprostatic inflammation. Serum trans fatty acids were not associated with intraprostatic inflammation. No significant associations were observed in cases; however, we could not rule out a positive association with linoleic acid and an inverse association with arachidonic acid. Thus, in the PCPT, we found that serum n-3 fatty acids were inversely, n-6 fatty acids were positively, and trans fatty acids were not associated with intraprostatic inflammation in controls. Although, in theory, inflammation could mediate associations of serum fatty acids with prostate cancer risk, our findings cannot explain the epidemiologic associations observed with n-3 and n-6 fatty acids.

Age-related cataract in men in the selenium and vitamin e cancer prevention trial eye endpoints study: a randomized clinical trial.

IMPORTANCE: Observational studies suggest a role for dietary nutrients such as vitamin E and selenium in cataract prevention. However, the results of randomized clinical trials of vitamin E supplements and cataract have been disappointing and are not yet available for selenium. OBJECTIVE: To test whether long-term supplementation with selenium and vitamin E affects the incidence of cataract in a large cohort of men. DESIGN, SETTING, AND PARTICIPANTS: The Selenium and Vitamin E Cancer Prevention Trial (SELECT) Eye Endpoints Study was an ancillary study of the Southwest Oncology Group-coordinated SELECT, a randomized placebo-controlled 4-arm trial of selenium and vitamin E conducted among 35,533 men, 50 years and older for African American participants and 55 years and older for all other men, at 427 participating sites in the United States, Canada, and Puerto Rico. A total of 11,267 SELECT participants from 128 SELECT sites participated in the SELECT Eye Endpoints ancillary study. INTERVENTIONS: Individual supplements of selenium (200 µg per day from L-selenomethionine) and vitamin E (400 IU per day of all rac-α-tocopheryl acetate). MAIN OUTCOMES AND MEASURES: Incident cataract was defined as a lens opacity, age related in origin, and responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-reports confirmed by medical record review. Cataract extraction was defined as the surgical removal of an incident cataract. RESULTS: During a mean (SD) of 5.6 (1.2) years of treatment and follow-up, 389 cases of cataract were documented. There were 185 cataracts in the selenium group and 204 in the no selenium group (hazard ratio, 0.91; 95 % CI, 0.75-1.11; P = .37). For vitamin E, there were 197 cases in the treated group and 192 in the placebo group (hazard ratio, 1.02; 95 % CI, 0.84-1.25; P = .81). Similar results were observed for cataract extraction. CONCLUSIONS AND RELEVANCE: These data from a large cohort of apparently healthy men indicate that long-term daily supplementation with selenium and/or vitamin E is unlikely to have a large beneficial effect on age-related cataract. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00784225.

Plasma tocopherols and risk of prostate cancer in the Selenium and Vitamin E Cancer Prevention Trial (SELECT).

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) showed higher prostate cancer incidence in men supplemented with high-dose α-tocopherol. We, therefore, examined whether presupplementation plasma α-tocopherol or γ-tocopherol was associated with overall or high-grade prostate cancer. A stratified case-cohort sample that included 1,746 incident prostate cancer cases diagnosed through June 2009 and a subcohort of 3,211 men was derived from the SELECT trial of 35,533 men. Plasma was collected at entry from 2001 to 2004, and median follow-up was 5.5 years (range, 0-7.9 years). Incidence of prostate cancer as a function of plasma α-tocopherol, γ-tocopherol, and supplementation with α-tocopherol or selenomethionine was estimated by the hazard ratio (HR). Plasma γ-tocopherol was not associated with prostate cancer. Men with higher α-tocopherol concentrations seemed to have risk similar to that of men with lower concentrations [overall HR for fifth (Q5) vs. first quintile (Q1), 1.21; 95 % confidence interval (CI), 0.88-1.66; P-trend = 0.24; in the trial placebo arm, Q5 HR, 0.85; 95% CI, 0.44-1.62; P-trend = 0.66]. We found a strong positive plasma α-tocopherol association among men receiving the trial selenomethionine supplement [Q5 HR, 2.04; 95% CI, 1.29-3.22; P-trend = 0.005]. A positive plasma α-tocopherol-prostate cancer association also seemed limited to high-grade disease (Gleason grade, 7-10; overall Q5 HR, 1.59; 95% CI, 1.13-2.24; P-trend = 0.001; among men receiving selenomethionine, Q5 HR, 2.12; 95% CI, 1.32-3.40; P-trend = 0.0002). Our findings indicate that higher plasma α-tocopherol concentrations may interact with selenomethionine supplements to increase high-grade prostate cancer risk, suggesting a biologic interaction between α-tocopherol and selenium itself or selenomethionine.

Plasma vitamin D and prostate cancer risk: results from the Selenium and Vitamin E Cancer Prevention Trial.

BACKGROUND: In vitro, animal, and ecological studies suggest that inadequate vitamin D intake could increase prostate cancer risk, but results of biomarker-based longitudinal studies are inconsistent. METHODS: Data for this case (n = 1,731) and cohort (n = 3,203) analysis are from the Selenium and Vitamin E Cancer Prevention Trial. Cox proportional hazard models were used to test whether baseline plasma vitamin D (25-hydroxy) concentration, adjusted for season of blood collection, was associated with the risk of total and Gleason score 2-6, 7-10, and 8-10 prostate cancer. RESULTS: There were U-shaped associations of vitamin D with total cancer risk: compared with the first quintile, HRs were 0.83 [95% confidence interval (CI), 0.66-1.03; P = 0.092], 0.74 (95% CI, 0.59-0.92; P = 0.008), 0.86 (95% CI, 0.69-1.07; P = 0.181), and 0.98 (95% CI, 0.78-1.21; P = 0.823), for the second through fifth quintiles, respectively. For Gleason 7-10 cancer, corresponding HRs were 0.63 (95% CI, 0.45-0.90; P = 0.010), 0.66 (95% CI, 0.47-0.92; P = 0.016), 0.79 (95% CI, 0.56-1.10; P = 0.165), and 0.88 (95% CI, 0.63-1.22; P = 0.436). Among African American men (n = 250 cases), higher vitamin D was associated with reduced risk of Gleason 7-10 cancer only: in the a posteriori contrast of quintiles 1-2 versus 3-5, the HR was 0.55 (95% CI, 0.31-0.97; P = 0.037), with no evidence of dose-response or a U-shaped association. CONCLUSIONS: Both low and high vitamin D concentrations were associated with increased risk of prostate cancer, and more strongly for high-grade disease. IMPACT: The optimal range of circulating vitamin D for prostate cancer prevention may be narrow. Supplementation of men with adequate levels may be harmful. Cancer Epidemiol Biomarkers Prev; 23(8); 1494-504. ©2014 AACR.

Baseline selenium status and effects of selenium and vitamin e supplementation on prostate cancer risk.

BACKGROUND: The Selenium and Vitamin E Cancer Prevention Trial found no effect of selenium supplementation on prostate cancer (PCa) risk but a 17% increased risk from vitamin E supplementation. This case-cohort study investigates effects of selenium and vitamin E supplementation conditional upon baseline selenium status. METHODS: There were 1739 total and 489 high-grade (Gleason 7-10) PCa cases and 3117 men in the randomly selected cohort. Proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for effects of supplementation within quintiles of baseline toenail selenium. Cox proportional hazards models were used to estimate hazard ratios, and all statistical tests are two-sided. RESULTS: Toenail selenium, in the absence of supplementation, was not associated with PCa risk. Selenium supplementation (combined selenium only and selenium + vitamin E arms) had no effect among men with low selenium status (<60th percentile of toenail selenium) but increased the risk of high-grade PCa among men with higher selenium status by 91% (P = .007). Vitamin E supplementation (alone) had no effect among men with high selenium status (≥40th percentile of toenail selenium) but increased the risks of total, low-grade, and high-grade PCa among men with lower selenium status (63%, P = .02; 46%, P = .09; 111%, P = .008, respectively). CONCLUSIONS: Selenium supplementation did not benefit men with low selenium status but increased the risk of high-grade PCa among men with high selenium status. Vitamin E increased the risk of PCa among men with low selenium status. Men should avoid selenium or vitamin E supplementation at doses that exceed recommended dietary intakes.

Future directions in the prevention of prostate cancer.

The high global incidence of prostate cancer has led to a focus on chemoprevention strategies to reduce the public health impact of the disease. Early studies indicating that selenium and vitamin E might protect against prostate cancer encouraged large-scale studies that produced mixed clinical results. Next-generation prostate cancer prevention trials validated the impact of 5α-reductase inhibitors in hormone-responsive prostate cancer, and these results were confirmed in follow-up studies. Other interventions on the horizon, involving both dietary and pharmacological agents, hold some promise but require further investigation to validate their efficacy. In this Review, we discuss the clinical and preclinical evidence for dietary and pharmacological prevention of prostate cancer and give an overview of future opportunities for chemoprevention.

Plasma phospholipid fatty acids and prostate cancer risk in the SELECT trial.

BACKGROUND: Studies of dietary ω-3 fatty acid intake and prostate cancer risk are inconsistent; however, recent large prospective studies have found increased risk of prostate cancer among men with high blood concentrations of long-chain ω-3 polyunsaturated fatty acids ([LCω-3PUFA] 20:5ω3; 22:5ω3; 22:6ω3]. This case-cohort study examines associations between plasma phospholipid fatty acids and prostate cancer risk among participants in the Selenium and Vitamin E Cancer Prevention Trial. METHODS: Case subjects were 834 men diagnosed with prostate cancer, of which 156 had high-grade cancer. The subcohort consisted of 1393 men selected randomly at baseline and from within strata frequency matched to case subjects on age and race. Proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations between fatty acids and prostate cancer risk overall and by grade. All statistical tests were two-sided. RESULTS: Compared with men in the lowest quartiles of LCω-3PUFA, men in the highest quartile had increased risks for low-grade (HR = 1.44, 95% CI = 1.08 to 1.93), high-grade (HR = 1.71, 95% CI = 1.00 to 2.94), and total prostate cancer (HR = 1.43, 95% CI = 1.09 to 1.88). Associations were similar for individual long-chain ω-3 fatty acids. Higher linoleic acid (ω-6) was associated with reduced risks of low-grade (HR = 0.75, 95% CI = 0.56 to 0.99) and total prostate cancer (HR = 0.77, 95% CI = 0.59 to 1.01); however, there was no dose response. CONCLUSIONS: This study confirms previous reports of increased prostate cancer risk among men with high blood concentrations of LCω-3PUFA. The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis. Recommendations to increase LCω-3PUFA intake should consider its potential risks.

Evaluation of vitamin E and selenium supplementation for the prevention of bladder cancer in SWOG coordinated SELECT.

PURPOSE: Epidemiological and biological evidence suggests a preventive effect of selenium and vitamin E on bladder cancer. We assessed the effect of selenium and/or vitamin E on bladder cancer development. MATERIALS AND METHODS: This was a secondary analysis of the randomized, placebo controlled SELECT (Selenium and Vitamin E Cancer Prevention Trial), which included 34,887 men randomly assigned to 4 groups (selenium, vitamin E, selenium plus vitamin E and placebo) in double-blind fashion between August 22, 2001 and June 24, 2004. The primary end point was bladder cancer incidence, as determined by routine clinical management. RESULTS: During a median followup of 7.1 years (IQR 6.4-8.0) 224 bladder cancer cases were recorded. Patients with bladder cancer were older, and more likely to be white and have a smoking history than those without bladder cancer. Most cancers were urothelial and nonmuscle invasive. There was no significant difference in the bladder cancer incidence between the 53 men in the placebo group and the 56 in the vitamin E group (HR 1.05, IQR 0.64-1.73, p=0.79), the 60 in the selenium group (HR 1.13, 0.70-1.84, p=0.52) or the 55 in the vitamin E plus selenium group (HR 1.05, 0.63-1.70, p=0.86). CONCLUSIONS: This secondary analysis showed no preventive effect of selenium or vitamin E alone or combined on bladder cancer in this population of men. Further studies are needed to assess the effect in women, and at different doses and formulations.

Chemoprevention of prostate cancer: an updated view.

OBJECTIVES: To place chemoprevention of prostate cancer in current clinical context. METHODS: Review of recently published updates of large, randomized, controlled trials of primary chemoprevention of prostate cancer. RESULTS: With extended post-intervention follow-up, SELECT demonstrated a 17% increased risk of prostate cancer relative to placebo in the vitamin E alone arm. Two other trials in men with high-grade PIN demonstrated no effect of selenium alone or in combination with soy and lycopene. Trials of 5α-reductase inhibitors show an approximate 25% relative risk reduction in men at average risk and in those with an "elevated" PSA and prior negative biopsy, but adoption of these agents in clinical practice has been limited by concerns over an apparently increased risk of high-grade disease. CONCLUSIONS: Primary prevention of prostate cancer remains an attractive goal because of its prevalence and treatment-related morbidity. Neither selenium nor vitamin E prevents prostate cancer. The benefit/risk ratio for 5α-reductase inhibitors can be improved by limiting their use to men at high risk.

Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT).

CONTEXT: The initial report of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) found no reduction in risk of prostate cancer with either selenium or vitamin E supplements but a statistically nonsignificant increase in prostate cancer risk with vitamin E. Longer follow-up and more prostate cancer events provide further insight into the relationship of vitamin E and prostate cancer. OBJECTIVE: To determine the long-term effect of vitamin E and selenium on risk of prostate cancer in relatively healthy men. DESIGN, SETTING, AND PARTICIPANTS: A total of 35,533 men from 427 study sites in the United States, Canada, and Puerto Rico were randomized between August 22, 2001, and June 24, 2004. Eligibility criteria included a prostate-specific antigen (PSA) of 4.0 ng/mL or less, a digital rectal examination not suspicious for prostate cancer, and age 50 years or older for black men and 55 years or older for all others. The primary analysis included 34,887 men who were randomly assigned to 1 of 4 treatment groups: 8752 to receive selenium; 8737, vitamin E; 8702, both agents, and 8696, placebo. Analysis reflect the final data collected by the study sites on their participants through July 5, 2011. INTERVENTIONS: Oral selenium (200 µg/d from L-selenomethionine) with matched vitamin E placebo, vitamin E (400 IU/d of all rac-α-tocopheryl acetate) with matched selenium placebo, both agents, or both matched placebos for a planned follow-up of a minimum of 7 and maximum of 12 years. MAIN OUTCOME MEASURES: Prostate cancer incidence. RESULTS: This report includes 54,464 additional person-years of follow-up and 521 additional cases of prostate cancer since the primary report. Compared with the placebo (referent group) in which 529 men developed prostate cancer, 620 men in the vitamin E group developed prostate cancer (hazard ratio [HR], 1.17; 99% CI, 1.004-1.36, P = .008); as did 575 in the selenium group (HR, 1.09; 99% CI, 0.93-1.27; P = .18), and 555 in the selenium plus vitamin E group (HR, 1.05; 99% CI, 0.89-1.22, P = .46). Compared with placebo, the absolute increase in risk of prostate cancer per 1000 person-years was 1.6 for vitamin E, 0.8 for selenium, and 0.4 for the combination. CONCLUSION: Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT00006392.