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1.  A Randomized Trial of Selenium Supplementation and Risk of Type-2 Diabetes, as Assessed by Plasma Adiponectin 
PLoS ONE  2012;7(9):e45269.
Background
Evidence that selenium affects the risk of type-2 diabetes is conflicting, with observational studies and a few randomized trials showing both lower and higher risk linked to the level of selenium intake and status. We investigated the effect of selenium supplementation on the risk of type-2 diabetes in a population of relatively low selenium status as part of the UK PRECISE (PREvention of Cancer by Intervention with SElenium) pilot study. Plasma adiponectin concentration, a recognised independent predictor of type-2 diabetes risk and known to be correlated with circulating selenoprotein P, was the biomarker chosen.
Methods
In a randomized, double-blind, placebo-controlled trial, five hundred and one elderly volunteers were randomly assigned to a six-month intervention with 100, 200 or 300 µg selenium/d as high-selenium or placebo yeast. Adiponectin concentration was measured by ELISA at baseline and after six months of treatment in 473 participants with one or both plasma samples available.
Results
Mean (SD) plasma selenium concentration was 88.5 ng/g (19.1) at baseline and increased significantly in the selenium-treatment groups. In baseline cross-sectional analyses, the fully adjusted geometric mean of plasma adiponectin was 14% lower (95% CI, 0–27%) in the highest than in the lowest quartile of plasma selenium (P for linear trend = 0.04). In analyses across randomized groups, however, selenium supplementation had no effect on adiponectin levels after six months of treatment (P = 0.96).
Conclusions
These findings are reassuring as they did not show a diabetogenic effect of a six-month supplementation with selenium in this sample of elderly individuals of relatively low selenium status.
Trial Registration
Controlled-Trials.com ISRCTN25193534
doi:10.1371/journal.pone.0045269
PMCID: PMC3446875  PMID: 23028897
2.  Randomized, Double-Blind, Placebo-Controlled, Phase III Chemoprevention Trial of Selenium Supplementation in Patients With Resected Stage I Non–Small-Cell Lung Cancer: ECOG 5597 
Journal of Clinical Oncology  2013;31(33):4179-4187.
Purpose
Selenium has been reported to have chemopreventive benefits in lung cancer. We conducted a double-blind, placebo-controlled trial to evaluate the incidence of second primary tumors (SPTs) in patients with resected non–small-cell lung cancer (NSCLC) receiving selenium supplementation.
Patients and Methods
Patients with completely resected stage I NSCLC were randomly assigned to take selenized yeast 200 μg versus placebo daily for 48 months. Participation was 6 to 36 months postoperatively and required a negative mediastinal node biopsy, no excessive vitamin intake, normal liver function, negative chest x-ray, and no other evidence of recurrence.
Results
The first interim analysis in October 2009, with 46% of the projected end points accumulated, showed a trend in favor of the placebo group with a low likelihood that the trial would become positive; thus, the study was stopped. One thousand seven hundred seventy-two participants were enrolled, with 1,561 patients randomly assigned. Analysis was updated in June 2011 with the maturation of 54% of the planned end points. Two hundred fifty-two SPTs (from 224 patients) developed, of which 98 (from 97 patients) were lung cancer (38.9%). Lung and overall SPT incidence were 1.62 and 3.54 per 100 person-years, respectively, for selenium versus 1.30 and 3.39 per 100 person-years, respectively, for placebo (P = .294). Five-year disease-free survival was 74.4% for selenium recipients versus 79.6% for placebo recipients. Grade 1 to 2 toxicity occurred in 31% of selenium recipients and 26% of placebo recipients, and grade ≥ 3 toxicity occurred in less than 2% of selenium recipients versus 3% of placebo recipients. Compliance was excellent. No increase in diabetes mellitus or skin cancer was detected.
Conclusion
Selenium was safe but conferred no benefit over placebo in the prevention of SPT in patients with resected NSCLC.
doi:10.1200/JCO.2013.49.2173
PMCID: PMC3821010  PMID: 24002495
3.  Selenium for preventing cancer 
Background
This review is an update of the first Cochrane publication on selenium for preventing cancer (Dennert 2011).
Selenium is a metalloid with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers.
Objectives
Two research questions were addressed in this review: What is the evidence for: an aetiological relation between selenium exposure and cancer risk in humans? andthe efficacy of selenium supplementation for cancer prevention in humans?
Search methods
We conducted electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 1), MEDLINE (Ovid, 1966 to February 2013 week 1), EMBASE (1980 to 2013 week 6), CancerLit (February 2004) and CCMed (February 2011). As MEDLINE now includes the journals indexed in CancerLit, no further searches were conducted in this database after 2004.
Selection criteria
We included prospective observational studies (cohort studies including sub-cohort controlled studies and nested case-control studies) and randomised controlled trials (RCTs) with healthy adult participants (18 years of age and older).
Data collection and analysis
For observational studies, we conducted random effects meta-analyses when five or more studies were retrieved for a specific outcome. For RCTs, we performed random effects meta-analyses when two or more studies were available. The risk of bias in observational studies was assessed using forms adapted from the Newcastle-Ottawa Quality Assessment Scale for cohort and case-control studies; the criteria specified in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the risk of bias in RCTs.
Main results
We included 55 prospective observational studies (including more than 1,100,000 participants) and eight RCTs (with a total of 44,743 participants). For the observational studies, we found lower cancer incidence (summary odds ratio (OR) 0.69, 95% confidence interval (CI) 0.53 to 0.91, N = 8) and cancer mortality (OR 0.60, 95% CI 0.39 to 0.93, N = 6) associated with higher selenium exposure. Gender-specific subgroup analysis provided no clear evidence of different effects in men and women (P value 0.47), although cancer incidence was lower in men (OR 0.66, 95% CI 0.42 to 1.05, N = 6) than in women (OR 0.90, 95% CI 0.45 to 1.77, N = 2). The most pronounced decreases in risk of site-specific cancers were seen for stomach, bladder and prostate cancers. However, these findings have limitations due to study design, quality and heterogeneity that complicate interpretation of the summary statistics. Some studies suggested that genetic factors may modify the relation between selenium and cancer risk-a hypothesis that deserves further investigation.
In RCTs, we found no clear evidence that selenium supplementation reduced the risk of any cancer (risk ratio (RR) 0.90, 95% CI 0.70 to 1.17, two studies, N = 4765) or cancer-related mortality (RR 0.81, 95% CI 0.49 to 1.32, two studies, N = 18,698), and this finding was confirmed when the analysis was restricted to studies with low risk of bias. The effect on prostate cancer was imprecise (RR 0.90, 95% CI 0.71 to 1.14, four studies, N = 19,110), and when the analysis was limited to trials with low risk of bias, the interventions showed no effect (RR 1.02, 95% CI 0.90 to 1.14, three studies, N = 18,183). The risk of non-melanoma skin cancer was increased (RR 1.44, 95% CI 0.95 to 1.17, three studies, N = 1900). Results of two trials-the Nutritional Prevention of Cancer Trial (NPCT) and the Selenium and Vitamin E Cancer Trial (SELECT)-also raised concerns about possible increased risk of type 2 diabetes, alopecia and dermatitis due to selenium supplements. An early hypothesis generated by NPCT that individuals with the lowest blood selenium levels at baseline could reduce their risk of cancer, particularly of prostate cancer, by increasing selenium intake has not been confirmed by subsequent trials. As the RCT participants were overwhelmingly male (94%), gender differences could not be systematically assessed.
Authors’ conclusions
Although an inverse association between selenium exposure and the risk of some types of cancer was found in some observational studies, this cannot be taken as evidence of a causal relation, and these results should be interpreted with caution. These studies have many limitations, including issues with assessment of exposure to selenium and to its various chemical forms, heterogeneity, confounding and other biases. Conflicting results including inverse, null and direct associations have been reported for some cancer types.
RCTs assessing the effects of selenium supplementation on cancer risk have yielded inconsistent results, although the most recent studies, characterised by a low risk of bias, found no beneficial effect on cancer risk, more specifically on risk of prostate cancer, as well as little evidence of any influence of baseline selenium status. Rather, some trials suggest harmful effects of selenium exposure. To date, no convincing evidence suggests that selenium supplements can prevent cancer in humans.
doi:10.1002/14651858.CD005195.pub3
PMCID: PMC4441528  PMID: 24683040
4.  Effect of Selenium and Vitamin E on Risk of Prostate Cancer and Other Cancers: The Selenium and Vitamin E Cancer Prevention Trial (SELECT) 
Context
Secondary analyses of two randomized controlled trials (RCTs) and supportive epidemiologic and preclinical indicated the potential of selenium and vitamin E for preventing prostate cancer.
Objective
To determine whether selenium or vitamin E or both could prevent prostate cancer with little or no toxicity in relatively healthy men.
Design, Setting, and Participants
Randomization of a planned 32,400 men to selenium, vitamin E, selenium plus vitamin E, and placebo in a double-blinded fashion. Participants were recruited and followed in community practices, local hospitals and HMOs, and tertiary cancer centers in the United States, Canada and Puerto Rico. Baseline eligibility included 50 years or older (African American) or 55 years or older (all others), a serum prostate-specific antigen (PSA) ≤ 4 ng/mL, and a digital rectal examination (DRE) not suspicious for prostate cancer. Between 2001 and 2004, 35,533 men (10% more than planned because of a faster-than-expected accrual rate) were randomly assigned to the four study arms, which were well balanced with respect to all potentially important risk factors.
Interventions
Oral selenium (200 µg/day from L-selenomethionine) and matched vitamin E placebo, vitamin E (400 IU/day of all rac-α-tocopheryl acetate) and matched selenium placebo, or the two combined or placebo plus placebo for a planned minimum of 7 and maximum of 12 years.
Main Outcome Measures
Prostate cancer (as determined by routine community diagnostic standards) and prespecified secondary outcomes including lung, colorectal and overall cancer.
Results
Study supplements were discontinued at the recommendation of the Data and Safety Monitoring Committee at a planned 7-year interim analysis because the evidence convincingly demonstrated no benefit from either study agent (p < 0.0001) and no possibility of a benefit to the planned degree with additional follow-up. As of October 23, 2008, median overall follow-up was 5.46 years (range, 4.17 and 7.33). Hazard ratios (number of prostate cancers, 99% confidence intervals [CIs]) for prostate cancer were 1.13 for vitamin E (n=473; CI, 0.91–1.41), 1.04 for selenium (n=432; CI, 0.83–1.30), and 1.05 for the combination (n=437; CI, 0.83–1.31) compared with placebo (n=416). There were no significant differences (all p-values > 0.15) in any prespecified cancer endpoints. There were nonsignificant increased risks of prostate cancer in the vitamin E arm (p=0.06; relative risk [RR]=1.13; 99% CI, 0l95–1.35) and of Type 2 diabetes mellitus in the selenium arm (p=0.16; RR=1.07; 99% CI, 0.94–1.22), but they were not observed in the combination arm.
Conclusion
Selenium or vitamin E, alone or in combination, did not prevent prostate cancer in this population at the doses and formulations used.
doi:10.1001/jama.2008.864
PMCID: PMC3682779  PMID: 19066370
5.  Vitamin E and the Risk of Prostate Cancer: Updated Results of The Selenium and Vitamin E Cancer Prevention Trial (SELECT) 
JAMA  2011;306(14):1549-1556.
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 non-statistically significant 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
SELECT randomized 35,533 men from 427 study sites in the United States, Canada and Puerto Rico in a double-blind manner between August 22, 2001 and June 24, 2004. Eligible men were 50 years or older (African Americans) or 55 years or older (all others) with a PSA ≤4.0 ng/mL and a digital rectal examination not suspicious for prostate cancer. Included in the analysis are 34,887 men randomly assigned to one of four treatment groups: selenium (n=8752), vitamin E (n=8737), both agents (n=8702), or placebo (n=8696). Data reflect the final data collected by the study sites on their participants through July 5, 2011.
Interventions
Oral selenium (200 μg/day 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 since the primary report. Hazard ratios (99% confidence intervals [CI]) and numbers of prostate cancers were 1.17(99% CI 1.004-1.36, p=.008, n=620) for vitamin E, 1.09 (99% CI 0.93-1.27, p=.18, n=575) for selenium, 1.05 (99%CI 0.89-1.22, p=.46, n=555) for selenium + vitamin E vs. 1.00 (n=529) for placebo.The absolute increase in risk compared with placebo for vitamin E, selenium and the combination were 1.6, 0.9 and 0.4 cases of prostate cancer per 1,000 person-years.
Conclusions
Dietary supplementation with Vitamin E significantly increases the risk of prostate cancer among healthy men.
Trial registration
clinicaltrials.gov identifier: NCT00006392
doi:10.1001/jama.2011.1437
PMCID: PMC4169010  PMID: 21990298
6.  Selenium and Vitamin E: Cell Type– and Intervention-Specific Tissue Effects in Prostate Cancer 
Background
Secondary analyses of two randomized, controlled phase III trials demonstrated that selenium and vitamin E could reduce prostate cancer incidence. To characterize pharmacodynamic and gene expression effects associated with use of selenium and vitamin E, we undertook a randomized, placebo-controlled phase IIA study of prostate cancer patients before prostatectomy and created a preoperative model for prostatectomy tissue interrogation.
Methods
Thirty-nine men with prostate cancer were randomly assigned to treatment with 200 μg of selenium, 400 IU of vitamin E, both, or placebo. Laser capture microdissection of prostatectomy biopsy specimens was used to isolate normal, stromal, and tumor cells. Gene expression in each cell type was studied with microarray analysis and validated with a real-time polymerase chain reaction (PCR) and immunohistochemistry. An analysis of variance model was fit to identify genes differentially expressed between treatments and cell types. A beta-uniform mixture model was used to analyze differential expression of genes and to assess the false discovery rate. All statistical tests were two-sided.
Results
The highest numbers of differentially expressed genes by treatment were 1329 (63%) of 2109 genes in normal epithelial cells after selenium treatment, 1354 (66%) of 2051 genes in stromal cells after vitamin E treatment, and 329 (56%) of 587 genes in tumor cells after combination treatment (false discovery rate = 2%). Validation of 21 representative genes across all treatments and all cell types yielded Spearman correlation coefficients between the microarray analysis and the PCR validation ranging from 0.64 (95% confidence interval [CI] = 0.31 to 0.79) for the vitamin E group to 0.87 (95% CI = 0.53 to 0.99) for the selenium group. The increase in the mean percentage of p53-positive tumor cells in the selenium-treated group (26.3%), compared with that in the placebo-treated group (5%), showed borderline statistical significance (difference = 21.3%; 95% CI = 0.7 to 41.8; P = .051).
Conclusions
We have demonstrated the feasibility and efficiency of the preoperative model and its power as a hypothesis-generating engine. We have also identified cell type– and zone-specific tissue effects of interventions with selenium and vitamin E that may have clinical implications.
doi:10.1093/jnci/djn512
PMCID: PMC2734116  PMID: 19244175
7.  Phase III Trial of Selenium to Prevent Prostate Cancer in Men with High-Grade Prostatic Intraepithelial Neoplasia: SWOG S9917 
The threat of prostate cancer (PC) and the significant and often negative impact of its treatment underscore the importance of prevention. High-grade prostatic intraepithelial neoplasia (HGPIN) has been identified as a potential premalignant lesion marking an increased risk of PC, and substantial evidence suggests that men with HGPIN are in need of PC prevention. In vitro, in vivo, epidemiologic, and clinical trial evidence that selenium supplementation protects against PC motivated the study we report here: A double-blind, randomized, placebo-controlled trial of selenium 200 (mcg/day) as selenomethionine in men with HGPIN. The primary endpoint was progression of HGPIN to PC over a three-year period. This NCI Intergroup trial was coordinated by the Southwest Oncology Group (SWOG). Of 619 enrolled patients, 423 randomized men with HGPIN (212, selenium; 211, placebo) were eligible (by central pathology review) and included in the primary analysis. Three-year cancer rates were 36.6% (placebo) versus 35.6% (selenium; P = 0.73, adjusted). The majority of patients who developed cancer on trial (70.8%, selenium, and 75.5%, placebo) had a Gleason score of ≤ 6; there were no differences in Gleason scores between the two arms. Subset analyses included the finding of a nonsignificantly reduced PC risk (relative risk = 0.82; 95% confidence interval, 0.40–1.69) in selenium versus placebo patients in the lowest quartile of baseline plasma selenium level (< 106 ng/ml). Overall, and in all other subsets defined by baseline blood selenium levels, selenium supplementation had no effect on PC risk. The 36% PC rate in men with HGPIN indicates the association of this lesion with an elevated PC risk. Future study in this setting should focus on selenium-deficient populations and selenium pharmacogenetics.
doi:10.1158/1940-6207.CAPR-10-0343
PMCID: PMC3208719  PMID: 21896650
Chemoprevention; selenium; prostate cancer; intraepithelial neoplasia; prevention; clinical trials
8.  Phase 3 clinical trial investigating the effect of selenium supplementation in men at high risk for prostate cancer 
The Prostate  2012;73(3):328-335.
Purpose
This study was conducted to investigate the effect of Se supplementation on prostate cancer incidence in men at high risk for prostate cancer.
Methods
A Phase 3 randomized, double-blind, placebo-controlled clinical trial was conducted in 699 men at high risk for prostate cancer (prostate specific antigen (PSA) >4 ng/ml and/or suspicious digital rectal examination and/or PSA velocity >0.75ng/ml/year), but with a negative prostate biopsy. Participants were randomized to receive daily oral placebo (N = 232), 200 µg selenium (N =234), or 400 µg selenium (N=233) as selenized yeast. They were followed every six months for up five years. The time to diagnosis of prostate cancer was compared between treatment groups using the Cox-proportional hazards model.
Result
Compared to placebo, the hazard ratios [95% confidence intervals] for risk of developing prostate cancer in the selenium 200 µg/day or the selenium 400 µg/day group were 0.94 [0.52, 1.7] and 0.90 [0.48, 1.7] respectively. PSA velocity in the selenium arms was not significantly different from that observed in the placebo group (p=0.18 and p=0.17, respectively).
Conclusion
Selenium supplementation appeared to have no effect on the incidence of prostate cancer in men at high risk. In conjunction with results of other studies, these data indicate that selenium supplementation may not have a role in prostate cancer chemoprevention.
doi:10.1002/pros.22573
PMCID: PMC4086804  PMID: 22887343
9.  Oral selenium supplementation has no effect on PSA velocity in men undergoing active surveillance for localized prostate cancer 
Introduction
The Nutritional Prevention of Cancer Trial demonstrated a 52% lower incidence of prostate cancer in men supplemented with selenium. As a result, our study was designed to assess whether selenium supplementation attenuates the progression of prostate cancer.
Methods
A Phase 2 randomized, double-blind, placebo-controlled clinical trial was conducted in men with localized non-metastatic prostate cancer who had elected to forgo active treatment and be followed by active surveillance. A total of 140 men were randomized to placebo (n=46), 200 μg/day (n=47) or 800 μg/day (n=47) selenium p.o. (as selenized yeast) and followed every 3 months for up to 5 years. PSA velocity was used as a marker of prostate cancer progression and was estimated using mixed effects regression.
Results
Adjusting for age, body mass index, baseline selenium, smoking, baseline PSA, race, PSA method, and Gleason score; PSA velocities for 200 μg/day and 800 μg/day treatment groups were not statistically significantly different from placebo (p = 0.32 and p = 0.61 respectively). In the highest quartile of baseline selenium, men supplemented with 800 μg selenium demonstrated PSA velocity statistically significantly higher as compared to placebo (p = 0.018).
Conclusions
Selenium supplementation did not show a protective effect on PSA velocity in subjects with localized prostate cancer. On the contrary, supplementation with high dose selenium was observed to be a risk factor for increased PSA velocity in men with high baseline plasma selenium concentrations.
Trial registration
clinicaltrials.gov (NCT00752739)
doi:10.1158/1940-6207.CAPR-09-0143
PMCID: PMC4533875  PMID: 20647337
Prostate cancer; clinical trial; PSA velocity; selenium; prostate cancer progression
10.  Selenium supplementation has no effect on serum glucose levels in men at high risk for Prostate Cancer 
Journal of diabetes  2013;5(4):465-470.
Background
Current literature regarding the effect of selenium supplementation on risk of diabetes is inconclusive. Hence a longitudinal study was conducted to investigate the effect of selenium supplementation on serum glucose levels in elderly men.
Methods
Data were obtained from 699 men participating in a randomized, double-blind, placebo-controlled Phase 3 clinical trial investigating the effect of two doses of selenium (200 and 400 μg/day) compared to placebo on incidence of prostate cancer. Subjects were followed every six months for up to five years. Serum glucose levels were obtained every six months. Mixed effects regression models were used to assess if rate of change of serum glucose levels was significantly different in the selenium supplemented groups as compared to placebo. Sensitivity analyses were performed to assess the robustness of findings and to minimize the possibility of residual bias due to fasting status.
Results
Of the total 2893 glucose measurements, 734 were carried out when the subject had been fasting for ≥ 8 hours. The changes in serum glucose levels during the course of the trial were not statistically significantly different as compared to placebo for the selenium 200 μg/day (p = 0.98) or selenium 400 μg/day (p = 0.81) treatment groups. Sensitivity analyses demonstrated comparable results for models using the total population and models restricted to subjects with only fasting glucose data.
Conclusion
These results do not support a relationship between selenium supplementation and risk of diabetes. Hence recommendations regarding selenium supplementation based on increased risk of diabetes seem premature.
doi:10.1111/1753-0407.12041
PMCID: PMC3966548  PMID: 23489776
selenium supplementation; serum glucose; prostate cancer
11.  Optimal Management of High-Risk T1G3 Bladder Cancer: A Decision Analysis 
PLoS Medicine  2007;4(9):e284.
Background
Controversy exists about the most appropriate treatment for high-risk superficial (stage T1; grade G3) bladder cancer. Immediate cystectomy offers the best chance for survival but may be associated with an impaired quality of life compared with conservative therapy. We estimated life expectancy (LE) and quality-adjusted life expectancy (QALE) for both of these treatments for men and women of different ages and comorbidity levels.
Methods and Findings
We evaluated two treatment strategies for high-risk, T1G3 bladder cancer using a decision-analytic Markov model: (1) Immediate cystectomy with neobladder creation versus (2) conservative management with intravesical bacillus Calmette-Guérin (BCG) and delayed cystectomy in individuals with resistant or progressive disease. Probabilities and utilities were derived from published literature where available, and otherwise from expert opinion. Extensive sensitivity analyses were conducted to identify variables most likely to influence the decision. Structural sensitivity analyses modifying the base case definition and the triggers for cystectomy in the conservative therapy arm were also explored. Probabilistic sensitivity analysis was used to assess the joint uncertainty of all variables simultaneously and the uncertainty in the base case results. External validation of model outputs was performed by comparing model-predicted survival rates with independent published literature. The mean LE of a 60-y-old male was 14.3 y for immediate cystectomy and 13.6 y with conservative management. With the addition of utilities, the immediate cystectomy strategy yielded a mean QALE of 12.32 y and remained preferred over conservative therapy by 0.35 y. Worsening patient comorbidity diminished the benefit of early cystectomy but altered the LE-based preferred treatment only for patients over age 70 y and the QALE-based preferred treatment for patients over age 65 y. Sensitivity analyses revealed that patients over the age of 70 y or those strongly averse to loss of sexual function, gastrointestinal dysfunction, or life without a bladder have a higher QALE with conservative therapy. The results of structural or probabilistic sensitivity analyses did not change the preferred treatment option. Model-predicted overall and disease-specific survival rates were similar to those reported in published studies, suggesting external validity.
Conclusions
Our model is, to our knowledge, the first of its kind in bladder cancer, and demonstrated that younger patients with high-risk T1G3 bladder had a higher LE and QALE with immediate cystectomy. The decision to pursue immediate cystectomy versus conservative therapy should be based on discussions that consider patient age, comorbid status, and an individual's preference for particular postcystectomy health states. Patients over the age of 70 y or those who place high value on sexual function, gastrointestinal function, or bladder preservation may benefit from a more conservative initial therapeutic approach.
Using a Markov model, Shabbir Alibhai and colleagues develop a decision analysis comparing cystectomy with conservative treatment for high-risk superficial bladder cancer depending on patient age, comorbid conditions, and preferences.
Editors' Summary
Background.
Every year, about 67,000 people in the US develop bladder cancer. Like all cancers, bladder cancer arises when a single cell begins to grow faster than normal, loses its characteristic shape, and moves into surrounding tissues. Most bladder cancers develop from cells that line the bladder (“transitional” cells) and most are detected before they spread out of this lining. These superficial or T1 stage cancers can be removed by transurethral resection of bladder tumor (TURBT). The urologist (a specialist who treats urinary tract problems) passes a small telescope into the bladder through the urethra (the tube through which urine leaves the body) and removes the tumor. If the tumor cells look normal under a microscope (so-called normal histology), the cancer is unlikely to return; if they have lost their normal appearance, the tumor is given a “G3” histological grade, which indicates a high risk of recurrence.
Why Was This Study Done?
The best treatment for T1G3 bladder cancer remains controversial. Some urologists recommend immediate radical cystectomy— surgical removal of the bladder, the urethra, and other nearby organs. This treatment often provides a complete cure but can cause serious short-term health problems and affects long-term quality of life. Patients often develop sexual dysfunction or intestinal (gut) problems and sometimes find it hard to live with a reconstructed bladder. The other recommended treatment is immunotherapy with bacillus Calmette-Guérin (BCG, bacteria that are also used to vaccinate against tuberculosis). Long-term survival is not always as good with this conservative treatment but it is less likely than surgery to cause short-term illness or to reduce quality of life. In this study, the researchers have used decision analysis (a systematic evaluation of the important factors affecting a decision) to determine whether immediate cystectomy or conservative therapy is the optimal treatment for patients with T1G3 bladder cancer. Decision analysis allowed the researchers to account for quality-of-life factors while comparing the health benefits of each treatment for T1G3 bladder cancer.
What Did the Researchers Do and Find?
Using a decision analysis model called a Markov model, the researchers calculated the months of life gained, and the quality of life expected to result, from each of the two treatments. To estimate the life expectancy (LE) associated with each treatment, the researchers incorporated the published probabilities of various outcomes of each treatment into their model. To estimate quality-adjusted life expectancy (QALE, the number of years of good quality life), they incorporated “utilities,” measures of relative satisfaction with outcomes. (A utility of 1 represents perfect health; death is assigned a value of 0, and outcomes considered less than ideal, but better than death, fall in between). For a sexually potent 60-year-old man with bladder cancer but no other illnesses, the average LE predicted by the model was nearly eight months longer with immediate cystectomy than with conservative treatment (both LEs predicted by this model matched those seen in clinical trials); the average QALE with cystectomy was 4.2 months longer than with conservative treatment. Having additional diseases decreased the benefit of immediate cystectomy but the treatment still gave a longer LE until the patient reached 70 years old, when conservative treatment became better. For QALE, this change in optimal treatment appeared at age 65. Finally, conservative treatment gave a higher QALE than immediate cystectomy for patients concerned about preserving sexual function or averse to living with intestinal problems or a reconstructed bladder.
What Do These Findings Mean?
As with all mathematical models, these results depend on the assumptions included in the model. In particular, because published probability and utility values are not available for some of the possible outcomes of the two treatments, the LE and QALE calculations could be inaccurate. Also, assigning numerical ratings to life experiences is generally something of a simplification, which could affect the reliability of the QALE (but not the LE) results. Nevertheless, these findings provide useful guidance for urologists trying to balance the benefits of immediate cystectomy or conservative treatment against the potential short-term and long-term effects of these treatments on patients' quality of life. Specifically, the results indicate that decisions on treatment for T1G3 bladder cancer should be based on a consideration of the patient's age and any coexisting disease coupled with detailed discussions with the patient about their attitudes regarding the possible health-related effects of cystectomy.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040284.
MedlinePlus encyclopedia page on bladder cancer (in English and Spanish)
Information for patients and professionals from the US National Cancer Institute on bladder cancer (in English and Spanish)
Information for patients on bladder cancer from the UK charity Cancerbackup
Online course on Decision Analysis in Health Care from George Mason University
doi:10.1371/journal.pmed.0040284
PMCID: PMC1989749  PMID: 17896857
12.  Moving a Randomized Clinical Trial into an Observational Cohort 
Clinical trials (London, England)  2012;10(1):131-142.
Background
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double blind, placebo-controlled prostate cancer prevention study funded by the National Cancer Institute and conducted by SWOG (Southwest Oncology Group). A total of 35,533 men were assigned randomly to one of four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, placebo + placebo. The independent Data and Safety Monitoring Committee recommended the discontinuation of study supplements because of the lack of efficacy for risk reduction and because futility analyses demonstrated no possibility of benefit of the supplements to the anticipated degree (25% reduction in prostate cancer incidence) with additional follow-up. Study leadership agreed that the randomized trial should be terminated but believed that the cohort should be maintained and followed as the additional follow-up would contribute important information to the understanding of the biologic consequences of the intervention. Since the participants no longer needed to be seen in person to assess acute toxicities or to be given study supplements, it was determined that the most efficient and cost-effective way to follow them was via a central coordinated effort.
Purpose
A number of changes were necessary at the local Study Sites and SELECT Statistical Center to transition to following participants via a Central Coordinating Center. We describe the transition process from a randomized clinical trial to the observational Centralized Follow-up (CFU) study.
Methods
The process of transitioning SELECT, implemented at more than 400 Study Sites across the United States, Canada and Puerto Rico, entailed many critical decisions and actions including updates to online documents such as the SELECT Workbench and Study Manual, a protocol amendment, reorganization of the Statistical Center, creation of a Transition Committee, development of materials for SELECT Study Sites, development of procedures to close Study Sites, and revision of data collection procedures and the process by which to contact participants.
Results
At the time of the publication of the primary SELECT results in December 2008, there were 32,569 men alive and currently active in the trial. As of December 31, 2011, 17,761 participants had been registered to the CFU study. This number is less than had been anticipated due to unforeseen difficulties with local Study Site IRBs. However, from this cohort we estimate that an additional 580 prostate cancer cases and 215 Gleason 7 or higher cancers will be identified. Over 109,000 individual items have been mailed to participants. Active SELECT ancillary studies have continued. The substantial SELECT biorepository is available to researchers; requests to use the specimens are reviewed for feasibility and scientific merit. As of April 2012, 12 proposals had been approved.
Limitations
The accrual goal of the follow-up study was not met, limiting our power to address the study objectives satisfactorily. The CFU study is also dependent on a number of factors including continued funding, continued interest of investigators in the biorepository and the continued contribution of the participants. Our experience may be less pertinent to investigators who wish to follow participants in a treatment trial or participants in prevention trials in other medical areas.
Conclusions
Extended follow-up of participants in prevention research is important to study the long-term effects of the interventions, such as those used in SELECT. The approach taken by SELECT investigators was to continue to follow participants centrally via an annual questionnaire and with a web-based option. The participants enrolled in the CFU study represent a large, well-characterized, generally healthy cohort. The CFU has enabled us to collect additional prostate and other cancer endpoints and longer follow-up on the almost 18,000 participants enrolled. The utility of the extensive biorepository that was developed during the course of the SELECT is enhanced by longer follow-up.
doi:10.1177/1740774512460345
PMCID: PMC3636982  PMID: 23064404
13.  Selenium and Prostate Cancer Prevention: Insights from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) 
Nutrients  2013;5(4):1122-1148.
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was conducted to assess the efficacy of selenium and vitamin E alone, and in combination, on the incidence of prostate cancer. This randomized, double-blind, placebo-controlled, 2 × 2 factorial design clinical trial found that neither selenium nor vitamin E reduced the incidence of prostate cancer after seven years and that vitamin E was associated with a 17% increased risk of prostate cancer compared to placebo. The null result was surprising given the strong preclinical and clinical evidence suggesting chemopreventive activity of selenium. Potential explanations for the null findings include the agent formulation and dose, the characteristics of the cohort, and the study design. It is likely that only specific subpopulations may benefit from selenium supplementation; therefore, future studies should consider the baseline selenium status of the participants, age of the cohort, and genotype of specific selenoproteins, among other characteristics, in order to determine the activity of selenium in cancer prevention.
doi:10.3390/nu5041122
PMCID: PMC3705339  PMID: 23552052
selenium; SELECT; prostate cancer; chemoprevention
14.  Randomized, double-blind, placebo-controlled trial of selenium supplements among HIV-infected pregnant women in Tanzania: effects on maternal and child outcomes2 
Background
In observational studies, adequate selenium status has been associated with better pregnancy outcomes and slowed HIV disease progression.
Objective
We investigated the effects of daily selenium supplements on CD4 cell counts, viral load, pregnancy outcomes, and maternal and infant mortality among 913 HIV-infected pregnant women.
Design
In this randomized, double-blind, placebo-controlled trial, eligible women between 12 and 27 wk of gestation were given daily selenium (200 μg as selenomethionine) or placebo as supplements from recruitment until 6 mo after delivery. All women received prenatal iron, folic acid, and multivitamin supplements irrespective of experimental assignment.
Results
The selenium regimen had no significant effect on maternal CD4 cell counts or viral load. Selenium was marginally associated with a reduced risk of low birth weight [relative risk (RR) = 0.71; 95% CI: 0.49, 1.05; P = 0.09] and increased risk of fetal death (RR = 1.58; 95% CI = 0.95, 2.63; P = 0.08), but had no effect on risk of prematurity or small-for-gestational age birth. The regimen had no significant effect on maternal mortality (RR = 1.02; 95% CI = 0.51, 2.04; P = 0.96). There was no significant effect on neonatal or overall child mortality, but selenium reduced the risk of child mortality after 6 wk (RR = 0.43; 95% CI = 0.19, 0.99; P = 0.048).
Conclusion
Among HIV-infected women from Dar es Salaam, Tanzania, selenium supplements given during and after pregnancy did not improve HIV disease progression or pregnancy outcomes, but may improve child survival. This trial was registered at clinical-trials.gov as NCT00197561.
PMCID: PMC2474659  PMID: 18541571
15.  No effect of selenium supplementation on serum glucose levels in men with prostate cancer 
The American journal of medicine  2010;123(8):765-768.
Background
Literature indicates a relationship between selenium supplementation and risk of diabetes. However, since these data are inconclusive we investigated the effect of selenium supplementation on serum glucose levels in men with prostate cancer enrolled in a clinical trial testing of the effect of selenium on prostate cancer progression.
Methods
Subjects were randomized to receive placebo (N = 46), selenium 200 µg/day (N = 47) and selenium 800 µg/day (N = 47). Serum glucose levels were obtained every six months for up to five years. Longitudinal analysis was carried out to assess if rate of change of serum glucose levels was significantly different in the selenium supplemented groups as compared to placebo. Sensitivity analyses were performed to assess the robustness of findings.
Results
Changes in serum glucose levels during the course of the trial were not statistically significantly different as compared to placebo for the selenium 200 µg/day (p = 0.56) or selenium 800 µg/day (p = 0.91) treatment groups.
Conclusion
These results do not support a relationship between selenium supplementation and changes in serum glucose levels. Recommendations regarding selenium supplementation and risk of diabetes will require more definitive studies.
doi:10.1016/j.amjmed.2010.02.018
PMCID: PMC2913148  PMID: 20670733
Selenium supplementation; serum glucose; prostate cancer
16.  Age-related Cataract in a Randomized Trial of Selenium and Vitamin E in Men: The SELECT Eye Endpoints (SEE) Study 
JAMA ophthalmology  2015;133(1):17-24.
Importance
Observational studies suggest a role for dietary nutrients such as vitamin E and selenium in cataract prevention. However, the results of randomized 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 SELECT Eye Endpoints (SEE) study was an ancillary study of the SWOG-coordinated Selenium and Vitamin E Cancer Prevention Trial (SELECT), a randomized, placebo-controlled, four arm trial of selenium and vitamin E conducted among 35,533 men aged 50 years and older for African Americans and 55 and older for all other men, at 427 participating sites in the US, Canada, and Puerto Rico. A total of 11,267 SELECT participants from 128 SELECT sites participated in the SEE ancillary study.
Intervention
Individual supplements of selenium (200 µg/d from L-selenomethionine) and vitamin E (400 IU/d of all rac-α-tocopheryl acetate).
Main Outcome Measures
Incident cataract, defined as a lens opacity, age-related in origin, responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-report confirmed by medical record review, and cataract extraction, 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 [HR], 0.91; 95 percent confidence interval [CI], 0.75 to 1.11; P=.37). For vitamin E, there were 197 cases in the treated group and 192 in the placebo group (HR, 1.02; CI, 0.84 to 1.25; P=.81). Similar results were observed for cataract extraction.
Conclusions and Relevance
These randomized trial 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.
doi:10.1001/jamaophthalmol.2014.3478
PMCID: PMC4395006  PMID: 25232809
17.  EFFECT OF SELENIUM SUPPLEMENTATION ON PROTEOMIC SERUM BIOMARKERS IN ELDERLY MEN 
The Journal of frailty & aging  2015;4(2):107-110.
Objectives
To determine the effect of selenium supplementation on the human proteomic profile.
Design
Serum samples were collected in this pilot study from a randomized placebo controlled Phase 2 clinical trial (Watchful Waiting (WW)).
Setting
Subjects were followed every three months for up to five years at the University of Arizona Prostate Cancer Prevention Program.
Participants
One hundred and forty men (age < 85 years) had biopsy-proven prostate cancer, a Gleason sum score less than eight, no metastatic cancer, and no prior treatment for prostate cancer.
Intervention
As part of the WW trial, men were randomized to placebo, selenium 200 μg/day or selenium 800 μg/day. For the purpose of the current study, 40 subjects enrolled in the WW study (20 from the placebo group and 20 from Se 800 μg/day group) were selected.
Measurements
Baseline serum samples were collected at each follow-up visit and stored at −80 degrees Celsius. A multiplexed proteomic panel investigated changes in 120 proteins markers simultaneously.
Results
Thirteen proteins (Apolipoprotein J, IL-10, IL-1 alpha, MMP-3, IL-12p70, IL-2 receptor alpha, cathepsin B, eotaxin, EGFR, FGF-basic, myeloperoxidase, RANTES, TGF-beta) were determined to be either statistically (p-value < 0.05) or marginally significantly (0.05 < p-value <0.1) changed in the selenium supplemented group as compared to placebo.
Conclusion
Although independent validation of these results is needed, this study is the first of its kind to utilize high throughput fluorescence based protein multiplex panel in analyzing changes in the proteomic profile due to selenium supplementation. Results from this study provide insight into the ability of selenium to modulate numerous protein markers and thus impact various biological processes in humans.
doi:10.14283/jfa.2015.48
PMCID: PMC4567258  PMID: 26366377
Selenium supplementation; proteomic biomarkers; elderly men
18.  Association of selenium status and blood glutathione concentrations in blacks and whites 
Nutrition and cancer  2011;63(3):367-375.
Selenium deficiency has been linked with increased cancer risk and, in some studies, selenium supplementation was protective against certain cancers. Previous studies suggest that selenium chemoprevention may involve reduced oxidative stress through enhanced glutathione (GSH). Our objectives were to examine the relationships between selenium and GSH in blood and modifying effects of race and sex in free living adults and individuals supplemented with selenium. Plasma selenium concentrations and free and bound GSH concentrations and γ-glutamyl cysteine ligase (GCL) activity in blood were measured in 336 healthy adults, (161 blacks, 175 whites). Plasma selenium and blood GSH were also measured in 36 healthy men from our previously conducted placebo-controlled trial of selenium-enriched yeast (247 μg/day for 9 months). In free-living adults, selenium concentrations were associated with increased blood GSH concentration and GCL activity (P<0.05). Further, selenium was significantly higher in whites than in blacks (P<0.01). After 9 months of supplementation, plasma selenium was increased 114% in whites and 50% in blacks (P<0.05) and blood GSH was increased 35% in whites (P<0.05) but was unchanged in blacks. These results indicate a direct association between selenium and GSH in blood of both free-living and selenium-supplemented individuals, with race being an important modifying factor.
doi:10.1080/01635581.2011.535967
PMCID: PMC3087599  PMID: 21462082
19.  Design and baseline characteristics of participants in a phase III randomized trial of celecoxib and selenium for colorectal adenoma prevention 
Cyclooxygenase (COX) inhibitors reduce colorectal adenoma recurrence by up to 45% and selenium supplementation may prevent colorectal cancer. Following colonoscopic adenoma resection, 1,600 men and women aged 40-80 years were randomized to celecoxib (400 mg daily), a selective COX-2 inhibitor, and/or selenium (200 μg daily as selenized yeast), or double placebo. The trial was initiated in November, 2001. The primary trial endpoint is adenoma recurrence in each intervention group compared to placebo, as determined by surveillance colonoscopy performed 3-5 years after baseline. Randomization was stratified by use of low-dose aspirin (81 mg) and clinic site. Following reports of cardiovascular toxicity associated with COX-2 inhibitors, the celecoxib arm was discontinued in December, 2004 when 824 participants had been randomized. Accrual continued with randomization to selenium alone or placebo. Randomization of the originally planned cohort (n=1,621) was completed in November, 2008. A further 200 patients with 1+ advanced adenomas (denoting increased risk for colorectal cancer) were accrued to enhance statistical power for determining intervention efficacy in this higher-risk subgroup. Accrual of the total cohort (n=1,824) was completed in January, 2011. Baseline cohort characteristics include: mean age 62.9 years; 65% male; BMI 29.1 ±5.1; 47% taking low-dose aspirin while on trial; 20% with 3+ adenomas; and 38% with advanced adenomas. Intervention effects on adenoma recurrence will be determined, and their modification by genetic background and baseline selenium level. The effect of selenium supplementation on risk for type 2 diabetes will also be reported (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00078897.)
doi:10.1158/1940-6207.CAPR-12-0204
PMCID: PMC3518663  PMID: 23060037
colorectal adenoma; celecoxib; selenium; randomized trial
20.  Selenium and Lung Cancer: A Systematic Review and Meta Analysis 
PLoS ONE  2011;6(11):e26259.
Background
Selenium is a natural health product widely used in the treatment and prevention of lung cancers, but large chemoprevention trials have yielded conflicting results. We conducted a systematic review of selenium for lung cancers, and assessed potential interactions with conventional therapies.
Methods and Findings
Two independent reviewers searched six databases from inception to March 2009 for evidence pertaining to the safety and efficacy of selenium for lung cancers. Pubmed and EMBASE were searched to October 2009 for evidence on interactions with chemo- or radiation-therapy. In the efficacy analysis there were nine reports of five RCTs and two biomarker-based studies, 29 reports of 26 observational studies, and 41 preclinical studies. Fifteen human studies, one case report, and 36 preclinical studies were included in the interactions analysis. Based on available evidence, there appears to be a different chemopreventive effect dependent on baseline selenium status, such that selenium supplementation may reduce risk of lung cancers in populations with lower baseline selenium status (serum<106 ng/mL), but increase risk of lung cancers in those with higher selenium (≥121.6 ng/mL). Pooling data from two trials yielded no impact to odds of lung cancer, OR 0.93 (95% confidence interval 0.61–1.43); other cancers that were the primary endpoints of these trials, OR 1.51 (95%CI 0.70–3.24); and all-cause-death, OR 0.93 (95%CI 0.79–1.10). In the treatment of lung cancers, selenium may reduce cisplatin-induced nephrotoxicity and side effects associated with radiation therapy.
Conclusions
Selenium may be effective for lung cancer prevention among individuals with lower selenium status, but at present should not be used as a general strategy for lung cancer prevention. Although promising, more evidence on the ability of selenium to reduce cisplatin and radiation therapy toxicity is required to ensure that therapeutic efficacy is maintained before any broad clinical recommendations can be made in this context.
doi:10.1371/journal.pone.0026259
PMCID: PMC3208545  PMID: 22073154
21.  SodiUm SeleniTe Adminstration IN Cardiac Surgery (SUSTAIN CSX-trial): study design of an international multicenter randomized double-blinded controlled trial of high dose sodium-selenite administration in high-risk cardiac surgical patients 
Trials  2014;15:339.
Background
Cardiac surgery has been shown to result in a significant decrease of the antioxidant selenium, which is associated with the development of multiorgan dysfunction and increased mortality. Thus, a large-scale study is needed to investigate the effect of perioperative selenium supplementation on the occurrence of postoperative organ dysfunction.
Methods/Design
We plan a prospective, randomized double-blind, multicenter controlled trial, which will be conducted in North and South America and in Europe. In this trial we will include 1,400 high-risk patients, who are most likely to benefit from selenium supplementation. This includes patients scheduled for non-emergent combined and/or complex procedures, or with a predicted operative mortality of ≥5% according to the EuroSCORE II. Eligible patients will be randomly assigned to either the treatment group (bolus infusion of 2,000 μg sodium selenite immediately prior to surgery, followed by an additional dosage of 2,000 μg at ICU admission, and a further daily supplementation of 1,000 μg up to 10 days or ICU discharge) or to the control group (placebo administration at the same time points).
The primary endpoint of this study is a composite of 'persistent organ dysfunction’ (POD) and/or death within 30 days from surgery (POD + death). POD is defined as any need for life-sustaining therapies (mechanical ventilation, vasopressor therapy, mechanical circulatory support, continuous renal replacement therapy, or new intermittent hemodialysis) at any time within 30 days from surgery.
Discussion
The SUSTAIN-CSX™ study is a multicenter trial to investigate the effect of a perioperative high dosage sodium selenite supplementation in high-risk cardiac surgical patients.
Trial registration
This trial was registered at Clinicaltrials.gov (identifier: NCT02002247) on 28 November 2013.
Electronic supplementary material
The online version of this article (doi:10.1186/1745-6215-15-339) contains supplementary material, which is available to authorized users.
doi:10.1186/1745-6215-15-339
PMCID: PMC4247649  PMID: 25169040
Selenium; Inflammatory response; Oxidative stress; Antioxidant capacity; Myocardial ischemia/reperfusion; Postoperative organ failure
22.  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.
doi:10.1093/jnci/djt456
PMCID: PMC3975165  PMID: 24563519
23.  Assessing Bladder Cancer Risk in Type 2 Diabetes Clinical Trials: the Dapagliflozin Drug Development Program as a ‘Case Study’ 
Diabetes Therapy  2015;6(3):357-375.
Introduction
Dapagliflozin, a sodium-glucose co-transporter 2 inhibitor, decreases plasma glucose levels by suppressing renal glucose reabsorption and increasing urinary glucose excretion. Previously published pre-clinical data suggest that dapagliflozin lacks carcinogenic potential. This article reviews data on bladder cancer with dapagliflozin to illustrate the challenges in assessing bladder cancer in drug development programs in patients with type 2 diabetes mellitus (T2DM).
Methods
Clinical cases of bladder cancer were analyzed in a pooled population of >9000 patients in 21 phase 2b/3 dapagliflozin clinical trials of up to 208 weeks’ duration.
Results
In the 21-study pool, demographic and baseline characteristics were generally consistent between dapagliflozin and comparator groups. The overall incidence of malignancies was also balanced between the treatment groups, with an incidence rate ratio (IRR) of 1.035 [95% confidence interval (CI): 0.724, 1.481]. Nine of 5936 dapagliflozin-treated patients and 1 of 3403 comparator-treated patients reported bladder cancer, with an IRR of 5.168 (95% CI: 0.677, 233.55). All of these patients had clinical attributes typical of bladder cancer in the general population (≥60-year-old males; 8 of the 10 patients were current/former smokers). All cases of bladder cancer were reported within 2 years of starting study treatment. There was an absence of detailed workup of hematuria prior to randomization, and no hematuria workup data were collected proactively in the dapagliflozin trials, which is typical of clinical practice. Failure to exclude bladder cancer prior to randomization increases the chance of recruiting patients with pre-existing bladder cancer in clinical trials and may delay the final diagnosis. Of the nine dapagliflozin-treated patients with bladder cancer, eight had microscopic hematuria prior to start of treatment or within 6 months of initiating study treatment.
Conclusion
The assessment of bladder cancer data illustrates the challenges of characterizing cancer risk in T2DM drug development programs. The totality of evidence to date does not suggest a causal relationship between dapagliflozin and bladder cancer.
Funding
AstraZeneca.
Electronic supplementary material
The online version of this article (doi:10.1007/s13300-015-0128-9) contains supplementary material, which is available to authorized users.
doi:10.1007/s13300-015-0128-9
PMCID: PMC4575305  PMID: 26323372
Bladder cancer; Dapagliflozin; Hematuria; SGLT2 inhibitor; Type 2 diabetes mellitus
24.  Effects of high doses of selenium, as sodium selenite, in septic shock: a placebo-controlled, randomized, double-blind, phase II study 
Critical Care  2007;11(4):R73.
Introduction
Sepsis is associated with the generation of oxygen free radicals and (lacking) decreased selenium plasma concentrations. High doses of sodium selenite might reduce inflammation by a direct pro-oxidative effect and may increase antioxidant cell capacities by selenium incorporation into selenoenzymes. We investigated the effects of a continuous administration of high doses of selenium in septic shock patients.
Methods
A prospective, multicentre, placebo-controlled, randomized, double-blind study was performed with an intention-to-treat analysis in severe septic shock patients with documented infection. Patients received, for 10 days, selenium as sodium selenite (4,000 μg on the first day, 1,000 μg/day on the nine following days) or matching placebo using continuous intravenous infusion. The primary endpoint was the time to vasopressor therapy withdrawal. The duration of mechanical ventilation, the mortality rates in the intensive care unit, at hospital discharge, and at 7, 14, 28 and 180 days and 1 year after randomization, and adverse events were recorded.
Results
Sixty patients were included (placebo, n = 29; selenium, n = 31). The median time to vasopressor therapy withdrawal was 7 days in both groups (95% confidence interval = 5–8 and 6–9 in the placebo and selenium groups, respectively; log-rank, P = 0.713). The median duration of mechanical ventilation was 14 days and 19 days in the placebo and selenium groups, respectively (P = 0.762). Mortality rates did not significantly differ between groups at any time point. Rates of adverse events were similar in the two groups.
Conclusion
Continuous infusion of selenium as sodium selenite (4,000 μg on the first day, 1,000 μg/day on the nine following days) had no obvious toxicity but did not improve the clinical outcome in septic shock patients. Trial Registration = NCT00207844.
doi:10.1186/cc5960
PMCID: PMC2206523  PMID: 17617901
25.  A randomized controlled trial of vitamin E and selenium on rate of decline in lung function 
Respiratory Research  2015;16(1):35.
Background
The intake of nutrients with antioxidant properties is hypothesized to augment antioxidant defenses, decrease oxidant damage to tissues, and attenuate age-related rate of decline in lung function. The objective was to determine whether long-term intervention with selenium and/or vitamin E supplements attenuates the annual rate of decline in lung function, particularly in cigarette smokers.
Methods
The Respiratory Ancillary Study (RAS) tested the single and joint effects of selenium (200 μg/d L-selenomethionine) and vitamin E (400 IU/day all rac-α-tocopheryl acetate) in a randomized double-blind placebo-controlled trial. At the end of the intervention, 1,641 men had repeated pulmonary function tests separated by an average of 3 years. Linear mixed-effects regression models estimated the effect of intervention on annual rate of decline in lung function.
Results
Compared to placebo, intervention had no main effect on either forced expiratory volume in the first second (FEV1) or forced expiratory flow (FEF25–75). There was no evidence for a smoking by treatment interaction for FEV1, but selenium attenuated rate of decline in FEF25–75 in current smokers (P = 0.0219). For current smokers randomized to selenium, annual rate of decline in FEF25–75 was similar to the annual decline experienced by never smokers randomized to placebo, with consistent effects for selenium alone and combined with vitamin E.
Conclusions
Among all men, there was no effect of selenium and/or vitamin E supplementation on rate of lung function decline. However, current smokers randomized to selenium had an attenuated rate of decline in FEF25–75, a marker of airflow.
Trial registration
Clinicaltrials.gov identifier: NCT00241865.
Electronic supplementary material
The online version of this article (doi:10.1186/s12931-015-0195-5) contains supplementary material, which is available to authorized users.
doi:10.1186/s12931-015-0195-5
PMCID: PMC4404242  PMID: 25889509
Spirometry; Vitamin E; Selenium; Forced expiratory volume; Forced expiratory flow rate

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