Equity in Cancer and Chronic Disease Prevention through a Multi-Pronged Network Intervention: Works-in-Progress

The increasing rates of cancer incidence are disproportionately borne by populations that are ineligible for screening and historically marginalized populations. To address this need, our community-centered model seeks to catalyze the widespread diffusion of evidence-based information and resources (e.g., community-based organizations, federally qualified health centers) to reduce the risks of cancer, chronic disease, and other conditions. In this study, we tested whether improving personal health literacy (i.e., confidence in seeking information) and enabling successful information transfer (i.e., intention to share the specific information learned through the program) among community residents could contribute to greater diffusion intention (i.e., number of network members with whom residents plan to share information and resources). The current study used post-intervention surveys, which were administered to Chicago residents who were 18 years or older and had participated in the program. Among the 1499 diverse Chicago residents, improved personal health literacy was associated with greater diffusion intention (ORs = 2.00-2.68, 95% CI [1.27-4.39], p ≤ 0.003). Successful information transfer was associated with greater diffusion, especially for cancer and other chronic disease risk reductions (ORs = 3.43-3.73, 95% CI [1.95-6.68], p < 0.001). The findings highlight the potential gains for health equity through sustainable, scalable, multi-sectoral partnerships.

Outcome of BMI2+: Motivational Interviewing to Reduce BMI Through Primary Care AAP PROS Practices

BACKGROUND

Pediatric obesity rates in the United States remain at an all-time high. Pediatric primary care clinicians and registered dietitians can help treat childhood obesity, and motivational interviewing (MI) has shown promising effects in prior trials.

METHODS

We randomized 18 pediatric primary care practices to receive the Brief Motivational Interviewing to Reduce BMI or BMI2+ intervention or continue with usual care (UC). Practices were recruited through the American Academy of Pediatrics Pediatric Research in Office Settings network. The intervention comprised 4 components1: in-person and telehealth MI counseling by pediatric clinicians; 4 recommended sessions,2 6 telephone MI counseling sessions from a registered dietitian,3 text message reminders and tailored motivational messages, and4 parent educational materials. The main outcome was the change in the percentage of the 95th percentile of BMI. The study was conducted 2017 through 2021.

RESULTS

There was a significant treatment x time interaction (b = 0.017, 95% confidence interval: [0.0066-0.027]) for the main outcome, favoring the UC group, with youth in the intervention arm showing a greater relative increase in their percent of the 95th percentile.

CONCLUSIONS

There was no overall benefit of the intervention and, contrary to expectations, youth in the intervention arm gained more weight, based on percent of the distance from the 95th percentile than matched youth from UC practices. The absolute excess weight gain among intervention relative to UC youth was small, approximately 0.5 BMI units and 1 kg over 2 years. We offer several potential explanations for these unexpected findings.

Construction and case study of a novel lung cancer risk index

PURPOSE

This study constructs a lung cancer risk index (LCRI) that incorporates many modifiable risk factors using an easily reproducible and adaptable method that relies on publicly available data.

METHODS

We used meta-analysis followed by Analytic Hierarchy Process (AHP) to generate a lung cancer risk index (LCRI) that incorporates seven modifiable risk factors (active smoking, indoor air pollution, occupational exposure, alcohol consumption, secondhand smoke exposure, outdoor air pollution, and radon exposure) for lung cancer. Using county-level population data, we then performed a case study in which we tailored the LCRI for use in the state of Illinois (LCRI_IL).

RESULTS

For both the LCRI and the LCRI_IL, active smoking had the highest weights (46.1% and 70%, respectively), whereas radon had the lowest weights (3.0% and 5.7%, respectively). The weights for alcohol consumption were 7.8% and 14.7% for the LCRI and the LCRI_IL, respectively, and were 3.8% and 0.95% for outdoor air pollution. Three variables were only included in the LCRI: indoor air pollution (18.5%), occupational exposure (13.2%), and secondhand smoke exposure (7.6%). The Consistency Ratio (CR) was well below the 0.1 cut point. The LCRI_IL was moderate though significantly correlated with age-adjusted lung cancer incidence (r = 0.449, P < 0.05) and mortality rates (r = 0.495, P < 0.05).

CONCLUSION

This study presents an index that incorporates multiple modifiable risk factors for lung cancer into one composite score. Since the LCRI allows data comprising the composite score to vary based on the location of interest, this measurement tool can be used for any geographic location where population-based data for individual risk factors exist. Researchers, policymakers, and public health professionals may utilize this framework to determine areas that are most in need of lung cancer-related interventions and resources.

Reducing paediatric overweight and obesity through motivational interviewing: study protocol for a randomised controlled trial in the AAP PROS research network

INTRODUCTION

Primary care remains an underused venue for prevention and management of paediatric overweight and obesity. A prior trial demonstrated a significant impact of paediatrician/nurse practitioner (Ped/NP)-and registered dietitian (RD)-delivered motivational interviewing (MI) on child body mass index (BMI). The study described here will test the effectiveness of an enhanced version of this primary care-based MI counselling intervention on child BMI.

METHODS AND ANALYSIS

This cluster randomised effectiveness trial includes 24 Ped/NPs from 18 paediatric primary care practices that belong to the American Academy of Pediatrics (AAP) national Pediatric Research in Office Settings (PROS) practice-based research network. To date, practices have been randomised (nine to intervention and nine to usual care). Intervention Ped/NPs have been trained in MI, behavioural therapy, billing/coding for weight management and study procedures. Usual care Ped/NPs received training in billing/coding and study procedures only. Children 3- 11 years old with BMI >the 85th percentile were identified via electronic health records (EHRs). Parents from intervention practices have been recruited and enrolled. Over about 2 years, these parents are offered approximately 10 MI-based counselling sessions (about four in person sessions with their child's Ped/NP and up to six telephonic sessions with a trained RD). The primary outcome is change in child BMI (defined as per cent from median BMI for age and sex) over the study period. The primary comparison is between eligible children in intervention practices whose parents enrol in the study and all eligible children in usual care practices. Data sources will include EHRs, billing records, surveys and counselling call notes.

ETHICS AND DISSEMINATION

Institutional Review Board approval was obtained from the AAP. All Ped/NPs provided written informed consent, and intervention group parents provided consent and Health Insurance Portability and Accountability Act (HIPAA) authorisation. Findings will be disseminated through peer-reviewed publications, conference presentations and appropriate AAP channels.

TRIAL REGISTRATION NUMBER

NCT03177148; Pre-results.

HPV vaccine recommendation profiles among a national network of pediatric practitioners: understanding contributors to parental vaccine hesitancy and acceptance

Background: Practitioner communication is one of the most important influences and predictors of HPV vaccination uptake. The objective of this study was to conduct a latent class analysis characterizing pediatric practitioner HPV recommendation patterns. Methods: Pediatric practitioners of the American Academy of Pediatrics' (AAP) Pediatric Research in Office Settings (PROS) national network completed an online survey where they were presented with 5 hypothetical vignettes of well child visits and responded to questions. Questions asked about their use of communication strategies, assessments about the adolescent patient becoming sexually active in the next 2 years for decision-making about HPV vaccine recommendation, and peer norms. Latent class analysis characterized practitioner subgroups based on their response patterns to 10 survey questions. Multinomial logistic regression examined practitioner characteristics associated with each profile. Results: Among 470 respondents, we identified three distinct practitioner HPV vaccine recommendation profiles: (1) Engagers (52%) followed national age-based guidelines, strongly recommended HPV vaccination, and perceived peers as strongly recommending; (2) Protocol Followers (20%) also strongly recommended HPV vaccination, but were less likely to engage families in a discussion about benefits; and (3) Ambivalent HPV Vaccine Recommenders (28%) delayed or did not recommend HPV vaccination and were more likely to use judgment about whether adolescents will become sexually active in the next two years. Practicing in a suburban setting was associated with twice the odds of being an Ambivalent Recommender relative to being an Engager (OR = 2.2; 95% CI:1.1-4.1). Conclusions: Findings underscore the importance of continued efforts to bolster practitioner adoption of evidence-based approaches to HPV vaccine recommendation especially among Ambivalent Recommenders.

Biological variation of routine haematology and biochemistry measurands in the horse

BACKGROUND

Clinical pathology results are typically interpreted by referring to population-based reference intervals. The use of individualised (subject-based) reference intervals is more appropriate for measurands with a high degree of variation between individuals.

OBJECTIVES

To determine the biological variation of routinely analysed equine haematology and biochemistry measurands and calculate indices of individuality and reference change values which enable production of individualised reference intervals, in a group of healthy, privately owned horses.

STUDY DESIGN

In a prospective cohort study, thirty-nine privately owned horses were sampled by jugular venipuncture for analysis of haematology and biochemistry measurands at weekly intervals for 6 weeks.

METHODS

Haematology was analysed on the day of collection. Serum was frozen and biochemistry analyses performed on thawed samples. Duplicate results were obtained and the coefficient of variation was calculated for analytical variation, within-subject variation and between-subject variation. The index of individuality and reference change value were derived for each measurand.

RESULTS

Haematology (red blood cell count, mean corpuscular haemoglobin and mean cell volume) and biochemistry measurands (total protein, globulins, albumin, gamma-glutamyl transferase, aspartate aminotransferase) demonstrated high individuality, indicating that individualised reference intervals are more appropriate for evaluation of these measurands. Two haematology (mean corpuscular haemoglobin concentration and platelets) and three biochemistry measurands (chloride, glucose and sodium) had low individuality, indicating that the use of traditional population-based reference intervals is appropriate for these measurands. Remaining measurands had intermediate individuality suggesting interpretation of the reference change value should occur with consideration of the population-based reference interval.

MAIN LIMITATIONS

The use of privately owned horses, variable management and environmental factors.

CONCLUSIONS

The use of individualised reference intervals is justified for many measurands in horses, supporting the use of serial sampling, consideration of biological variation and application of reference change values for improved clinical decision making and patient management in equine practice.

Serum phytanic and pristanic acid levels and prostate cancer risk in Finnish smokers

Phytanic acid is a saturated branched-chain fatty acid found predominantly in red meat and dairy products, and may contribute to the elevated risks of prostate cancer associated with higher consumption of these foods. Pristanic acid is formed during peroxisomal oxidation of phytanic acid, and is the direct substrate of α-Methyl-CoA-Racemase (AMACR)--an enzyme that is consistently overexpressed in prostate tumors relative to benign tissue. We measured phytanic and pristanic acids as percentages of total fatty acids by gas chromatography-mass spectrometry in prediagnostic blood samples from 300 prostate cancer cases and 300 matched controls, all of whom were participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study supplementation trial and follow-up cohort. In addition to providing a fasting blood sample at baseline, all men completed extensive diet, lifestyle, and medical history questionnaires. Among controls, the strongest dietary correlates of serum phytanic and pristanic acids were saturated fat, dairy fat, and butter (r = 0.50 and 0.40, 0.46 and 0.38, and 0.40 and 0.37, respectively; all P-values <0.001). There was no association between serum phytanic acid and risk of total or aggressive prostate cancer in multivariate logistic regression models (for increasing quartiles, odds ratios (OR) and 95% confidence intervals (CI) for aggressive cancer were 1.0 (referent), 1.62 (0.97-2.68), 1.12 (0.66-1.90), and 1.14 (0.67-1.94), P(trend) = 0.87). Pristanic acid was strongly correlated with phytanic acid levels (r = 0.73, P < 0.0001), and was similarly unrelated to prostate cancer risk. Significant interactions between phytanic and pristanic acids and baseline circulating β-carotene concentrations were noted in relation to total and aggressive disease among participants who did not receive β-carotene supplements as part of the original ATBC intervention trial. In summary, we observed no overall association between serum phytanic and pristanic acid levels and prostate cancer risk. Findings indicating that the direction and magnitude of these associations depended upon serum levels of the antioxidant β-carotene among men not taking β-carotene supplements should be interpreted cautiously, as they are likely due to chance.

Phytanic acid and the risk of non-Hodgkin lymphoma

Greater consumption of red meat, processed meat and dairy products has been associated with an increased risk of non-Hodgkin lymphoma (NHL) in several previous reports. Phytanic acid, a saturated fatty acid obtained primarily through the consumption of ruminant meat and dairy products, may offer a potential underlying mechanism for these associations. In a population-based case-control study of 336 cases and 460 controls conducted in Nebraska during 1999-2002, we examined whether phytanic acid-containing foods or total phytanic acid intake, estimated from a food frequency questionnaire and the published phytanic acid values of 151 food items, were associated with increased NHL risk. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals for overall NHL and the common NHL histologic subtypes. In multivariable models, higher intakes of density-adjusted beef [OR(T3 vs. T1) = 1.5 (1.1-2.2); P(trend) = 0.02], total dairy products [OR = 1.5 (1.1-2.2); P(trend) = 0.02) and milk [OR = 1.6 (1.1-2.3); P(trend) = 0.01] were associated with an increased risk of NHL. Intake of total phytanic acid was positively associated with NHL risk [OR = 1.5 (1.0-2.1); P(trend) = 0.04]. In analyses stratified by NHL subtype, greater consumption of beef was associated with an increased risk of diffuse large B-cell lymphoma, and greater consumption of milk was associated with an increased risk of follicular lymphoma (FL). Total phytanic acid intake was associated with an increased risk of FL and small lymphocytic lymphoma/chronic lymphocytic leukemia. Our results provide support that total phytanic acid and phytanic acid-containing foods may increase NHL risk.

Inverse association between glutathione peroxidase activity and both selenium-binding protein 1 levels and Gleason score in human prostate tissue

BACKGROUND

Data from human epidemiological studies, cultured mammalian cells, and animal models have supported a potentially beneficial role of selenium (Se) in prostate cancer prevention. In addition, Se-containing proteins including members of the glutathione peroxidase (GPx) family and Selenium-Binding Protein 1 (SBP1) have been linked to either cancer risk or development. For example, SBP1 levels are typically reduced in tumors compared to non-cancerous tissue, with the degree of reduction associated with increasingly poor clinical outcome.

METHODS

In order to investigate inter-relationships between blood and tissue Se levels and GPx activity, tissue SBP1 levels, and disease aggressiveness using the Gleason score, we measured levels of selenium and selected selenoproteins in fasting serum and histologically normal prostate tissues obtained from 24 men undergoing radical prostatectomy for the treatment of localized prostate cancer.

RESULTS

GPx enzyme activity was inversely correlated with SBP1 levels in prostate tissue as determined by densitometry of Western blots obtained using anti-SBP1 antibodies [partial Spearman's correlation coefficients and corresponding P-values overall and in African-Americans = -0.42 (0.08) and -0.53 (0.10), respectively], which is consistent with previous observations in cultured cells and mice. Of particular interest was the positive correlation between tissue GPx activity and Gleason score, with this relationship achieving statistical significance among African-Americans (r = 0.67, P = 0.02).

CONCLUSION

These studies support the continued investigation of the role of Se and selenoproteins in prostate cancer prevention, development, and prognosis.

Genome-wide association study identifies three common variants associated with serologic response to vitamin E supplementation in men

Vitamin E inhibits lipid peroxidation in cell membranes, prevents oxidative damage to DNA by scavenging free radicals, and reduces carcinogen production. No study to our knowledge, however, has examined the association between genetic variants and response to long-term vitamin E supplementation. We conducted a genome-wide association study (GWAS) of common variants associated with circulating α-tocopherol concentrations following 3 y of controlled supplementation. The study population included 2112 middle-aged, male smokers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort who received a trial supplementation of α-tocopherol (50 mg/d) and had fasting serum α-tocopherol concentrations measured after 3 y. Serum concentrations were log-transformed for statistical analysis and general linear models adjusted for age, BMI, serum total cholesterol, and cancer case status. Associations with serum response to α-tocopherol supplementation achieved genome-wide significance for 2 single nucleotide polymorphisms (SNP): rs964184 on 11q23.3 (P = 2.6 × 10(-12)) and rs2108622 on 19pter-p13.11 (P = 2.2 × 10(-7)), and approached genome-wide significance for one SNP, rs7834588 on 8q12.3 (P = 6.2 × 10(-7)). Combined, these SNP explain 3.4% of the residual variance in serum α-tocopherol concentrations during controlled vitamin E supplementation. A GWAS has identified 3 genetic variants at different loci that appear associated with serum concentrations after vitamin E supplementation in men. Identifying genetic variants that influence serum nutrient biochemical status (e.g., α-tocopherol) under supplementation conditions improves our understanding of the biological determinants of these nutritional exposures and their associations with cancer etiology.

Abstract 4463: Serum phytanic acid and prostate cancer risk: Results from a nested case-control study

Phytanic acid is a saturated branched chain fatty acid found predominantly in red meat and dairy products, and may contribute to the elevated risks of prostate cancer associated with higher consumption of these foods. We measured phytanic acid as a percentage of total fatty acids by gas chromatography-mass spectrometry in prediagnostic blood samples from 300 prostate cancer cases and 300 matched controls, all of whom were participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. In addition to providing a fasting blood sample at baseline, all men completed extensive diet, lifestyle, and medical history questionnaires. Among controls, the strongest dietary correlates of serum phytanic acid were dairy fat, butter, and saturated fat (r=0.45, 0.42, and 0.40, respectively; all p-values &lt;0.001). With the exception of lamb (r=0.18, p = 0.002), red meat intake was not significantly correlated with phytanic acid. There was no association between serum phytanic acid and risk of total or aggressive prostate cancer in multivariate logistic regression models. However, a significant interaction between phytanic acid and baseline concentrations of beta-carotene was noted in relation to advanced disease (p-interaction = 0.04). Among men with lower beta-carotene levels, serum phytanic acid was suggestively associated with elevated risks of advanced prostate cancer (odds ratios and 95% confidence intervals for increasing phytanic acid tertiles = 1.0 (referent), 1.42 (0.78-2.59), and 1.80 (0.91-3.55); p trend = 0.08) whereas the opposite relationship was noted among participants with higher beta-carotene levels (for increasing phytanic acid tertiles, odds ratios and 95% confidence intervals = 1.0 (referent), 1.03 (0.52-2.06), and 0.59 (0.30-1.17); p trend = 0.06). Our findings indicate that serum phytanic acid may be associated with increased risks of advanced prostate cancer in men with low levels of the antioxidant beta-carotene.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4463. doi:1538-7445.AM2012-4463

Estimated phytanic acid intake and prostate cancer risk: a prospective cohort study

Phytanic acid is a saturated fatty acid found predominantly in red meat and dairy products and may contribute to increases in prostate cancer risk that are observed with higher intakes of these foods. We constructed a novel summary measure of phytanic acid intake and prospectively examined its association with prostate cancer risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study--a cohort of Finnish male smokers aged 50-69 years. Diet was assessed at baseline in 27,111 participants using a validated 276-item dietary questionnaire. Since phytanic acid is not currently included in food composition tables, we used the published phytanic acid content of 151 major food items to estimate total daily intake. During up to 21 years of follow-up, a total of 1,929 incident prostate cancer cases (including 438 advanced cases) were identified. Higher phytanic acid intake, though unrelated to the risk of localized disease [relative risks (RR) and 95% confidence intervals (CI) for increasing quartiles of intake = 1.00 (ref), 0.83 (0.68-1.01), 0.76 (0.62-0.94) and 0.91 (0.74-1.13); p trend = 0.23], was associated with increased risks of advanced prostate cancer [RR and 95% CI = 1.00 (ref), 1.43 (1.09-1.89), 1.31 (0.99-1.75) and 1.38 (1.02-1.89); p trend = 0.06]. This association appeared to be driven predominantly by phytanic acid obtained from dairy products (particularly butter). Our study indicates that phytanic acid may contribute to previously observed associations between high-fat animal foods (particularly dairy products) and prostate cancer risk, although some caution is warranted as it may be acting as a surrogate marker of dairy fat.

Associations between functional polymorphisms in antioxidant defense genes and urinary oxidative stress biomarkers in healthy, premenopausal women

Functional polymorphisms in endogenous antioxidant defense genes including manganese superoxide dismutase (MnSOD), catalase (CAT), and glutathione peroxidase (GPX-1) have been linked with risk of cancer at multiple sites. Although it is presumed that these germline variants impact disease risk by altering the host's ability to detoxify mutagenic reactive oxygen species, very few studies have directly examined this hypothesis. Concentrations of 8-isoprostane F2α (8-iso-PGF2α) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxoxdG)-sensitive indicators of lipid peroxidation and DNA oxidation, respectively-were measured in 24-h urine samples obtained from 93 healthy, premenopausal women participating in a dietary intervention trial. In addition, DNA was extracted from blood for genotyping of MnSOD Val16Ala, CAT-262 C > T, and GPX1 Pro198Leu genotypes by Taqman assay. Although geometric mean concentrations of 8-iso-PGF2(α) and 8-oxoxdG varied across several study characteristics including race, education level, body mass index, and serum antioxidant levels, there was little evidence that these biomarkers differed across any of the examined genotypes. In summary, functional polymorphisms in endogenous antioxidant defense genes do not appear to be strongly associated with systemic oxidative stress levels in young, healthy women.

Genome-wide association study identifies common variants associated with circulating vitamin E levels

In genome-wide association studies (GWAS) of common genetic variants associated with circulating alpha- and gamma-tocopherol concentrations in two adult cohorts comprising 5006 men of European descent, we observed three loci associated with alpha-tocopherol levels, two novel single-nucleotide polymorphisms (SNPs), rs2108622 on 19pter-p13.11 (P= 1.7 × 10(-8)) and rs11057830 on 12q24.31 (P= 2.0 × 10(-8)) and confirmed a previously reported locus marked by rs964184 on 11q23.3 (P= 2.7 × 10(-10)). The three SNPs have been reported to be associated with lipid metabolism and/or regulation. We replicated these findings in a combined meta-analysis with two independent samples, P= 7.8 × 10(-12) (rs964184 on 11q23.3 near BUD13, ZNF259 and APOA1/C3/A4/A5), P= 1.4 × 10(-10) (rs2108622 on 19pter-p13.11 near CYP4F2) and P= 8.2 × 10(-9) (rs11057830 on 12q24.31 near SCARB1). Combined, these SNPs explain 1.7% of the residual variance in log alpha-tocopherol levels. In one of the two male GWAS cohorts (n= 992), no SNPs were significantly associated with gamma-tocopherol concentrations after including data from the replication sample for 71 independent SNPs with P< 1 × 10(-4) identified.

The inter-tidal zone is the pathway of input of enterococci to a subtropical recreational marine beach

Efforts were made to evaluate the source of enterococci levels at a recreational beach. Four monitoring efforts were implemented which included tidal studies, hourly sampling, runoff sampling, and spatially intensive sediment sampling. Spatially intensive sediment sampling indicated that enterococci concentrations consistently decreased away from the inter-tidal zone, both seaward and landward. During dry conditions, the highest concentrations in the water were observed during high tide (71±48 CFU/100 mL) and lower concentrations were observed during low tide (4±3 CFU/100 mL). Runoff was characterised by very high levels (11,700 CFU/100 mL). Results from these monitoring efforts collectively showed that the source of enterococci to the study beach is geographically located within the inter-tidal zone. Wash-in from the inter-tidal zone through tidal action and runoff plays a major role in controlling enterococci levels within the water column. Such results are significant in identifying the source and transport mechanisms of enterococci, which can subsequently be used as part of a modelling effort aimed at predicting enterococci levels at recreational beaches.

Dietary supplements and human health: for better or for worse?

Encouraged by the potential health benefits of higher dietary intake of substances with beneficial properties, the use of supplements containing these compounds has increased steadily over recent years. The effects of several of these, many of which are antioxidants, have been supported by data obtained in vitro, in animal models, and often by human studies as well. However, as carefully controlled human supplementation trials have been conducted, questions about the efficacy and safety of these supplements have emerged. In this Educational Paper, three different supplements were selected for consideration of the benefits and risks currently associated with their intake. The selected supplements include β-carotene, selenium, and genistein. The use of each is discussed in the context of preclinical and clinical data that provide evidence for both their use in reducing disease incidence and the possible liabilities that accompany their enhanced consumption. Variables that may influence their impact, such as lifestyle habits, baseline nutritional levels, and genetic makeup are considered and the application of these issues to broader classes of supplements is discussed.

Abstract B91: Functional polymorphisms in endogenous antioxidant defense genes and oxidative stress levels in women: A genotype-phenotype study

Superoxide dismutase, glutathione peroxidase, and catalase are the primary endogenous antioxidant defense enzymes that provide protection against reactive oxygen species — molecules that are known to cause damage to DNA, lipids, and proteins. The genes that encode these antioxidant enzymes are polymorphic, and three common single nucleotide polymorphisms — MnSOD Val16Ala, GPX1 Pro198 Leu, and CAT −262 C&gt;T -yield enzymes that display altered activity. These variants have been linked with risks of cancer at multiple sites, either directly or indirectly through interactions with dietary intakes of antioxidant nutrients or antioxidant-rich foods. Although it is generally presumed that these polymorphisms influence cancer risk by altering the host's ability to combat toxic free radicals, very few studies have directly tested this hypothesis in non-diseased individuals. We therefore evaluated whether urinary concentrations of 8-isoprostane F2 (8-iso-PGF2α) — the most sensitive indicator of lipid peroxidation, a biomarker for oxidative stress — vary across the aforementioned antioxidant defense genotypes in 87 young, healthy women randomized to the control arm of the Diet and Hormone Study — a low fat, high fruit and vegetable dietary intervention trial. 8-iso-PGF2α was measured in pre-randomization 24-hour urine samples by liquid chromatography- tandem mass spectrometry, and genotypes were determined in DNA extracted from buffy coat using the Taqman assay. 8-iso-PGF2α concentrations were significantly higher in overweight women, in those who were less well educated, and among participants with low serum β-carotene levels or high dietary intakes of γ-tocopherol or iron. Lipid peroxidation levels did not vary with age, race, smoking status, alcohol consumption, physical activity, fruit and vegetable intake, or vitamin supplement use. In multiple linear regression models, there was no evidence of a trend in urinary 8-iso-PGF2α concentrations across the MnSOD Val16Ala or GPX1 Pro198 Leu genotypes (for MnSOD val/val, ala/val, and ala/ala genotypes, mean 8-iso-PGF2α = 173, 213, and 193 pg/mL, respectively, p-trend = 0.63; for GPX1 Pro/Pro, Leu/Pro, and Leu/Leu genotypes, mean 8-iso-PGF2α = 185, 263, and 190 pg/mL, respectively, p-trend = 0.18). Contrary to expectation, urinary 8-iso-PGF2α concentrations decreased across the CAT −262 C&gt;T genotypes such that carriers of the homozygous (less active) TT genotype exhibited the lowest lipid peroxidation levels (for CC, TC, and TT genotypes, mean 8-iso-PGF2α = 232, 179, and 93 pg/mL, respectively, p-trend=0.07). These results indicate that functional polymorphisms in endogenous antioxidant defense genes do not correspond with higher lipid peroxidation levels in young, healthy women. Ongoing analyses will determine whether urinary concentrations of 8-hydroxydeoxguanosine — a biomarker of DNA damage — vary across these antioxidant defense genotypes.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):B91.

Variable expression of extracellular polysaccharide in the marine bacterium Pseudomonas atlantica is controlled by genome rearrangement

Production of extracellular polysaccharide by the marine bacterium Pseudomonas atlantica is a variable trait. Strains that produce extracellular polysaccharide (EPS(+)) have a mucoid colony phenotype, but during cultivation in the laboratory nonmucoid, EPS(-) variants arise that have a crenated colony morphology. This change is reversible since crenated variants rapidly switch to the original mucoid phenotype. We have cloned the locus (eps) controlling variable expression of EPS production by screening a recombinant cosmid library for clones that restore EPS production in the crenated variant. By using eps as a probe of genomic structure in variant strains, expression of EPS production was found to be controlled by a specific DNA rearrangement. Insertion of a 1.2-kilobase-pair DNA sequence in the eps locus results in EPS(-), whereas excision of the sequence restores the EPS(+) phenotype. Properties of the rearrangement suggest the involvement of a mobile genetic element. The possible significance of this DNA rearrangement to the survival of P. atlantica in the ocean is discussed.

Effects of beta-carotene supplementation on molecular markers of lung carcinogenesis in male smokers

Two primary prevention trials unexpectedly showed adverse effects of supplemental beta-carotene on lung cancer incidence in cigarette smokers. To elucidate the molecular mechanisms that might underlie these effects, we studied the immunohistochemical expression of cytochrome P450 1A1, 1A2, and 2E1, retinoic acid receptor beta, activated protein-1 elements, cyclin D1, and Ki67 in lung tumors and, when available, adjacent normal tissues obtained from incident cases in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Archival lung tissue was available from 52 men randomized to receive 20 mg of beta-carotene per day and 30 men randomized to the placebo arm, all of whom were diagnosed with incident non-small-cell lung carcinoma during the course of the trial and subsequently underwent radical pulmonary resection. In normal-appearing bronchial epithelium, positive staining for cyclin D1 was observed in 23% of cases in the beta-carotene group and 0% of cases in the placebo group (based on only 3 of 13 versus 0 of 11 cases staining positively, however; P = 0.04), with no differences in expression noted in lung tumor tissue (P = 0.48). There were no statistically significant differences in Ki67 expression in normal or cancerous lung tissue between intervention groups, although a small increase in staining in tumors was noted among cases in the beta-carotene versus placebo group (88% versus 71% of cases stained positive, respectively; P = 0.13). Contrary to expectation, beta-carotene supplementation had no apparent effect on retinoic acid receptor-beta expression. These findings suggest that male smokers supplemented with beta-carotene may have had an increased risk of lung cancer due to aberrant cell growth, although our results are based on a relatively small number of cases and require confirmation in other completed trials of beta-carotene supplementation.

No association between fruit, vegetables, antioxidant nutrients and risk of renal cell carcinoma

Previous epidemiologic studies that have examined the relationship between renal cell carcinoma (RCC) risk and intakes of plant foods and antioxidant nutrients have yielded inconsistent results. We therefore examined the associations between intakes of fruit, vegetables, carotenoids, flavonoids, vitamin E and vitamin C and RCC risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study cohort. At baseline, 27,062 male Finnish smokers aged 50-69 years completed a 276-item dietary questionnaire that included questions on frequency of consumption and portion size. During up to 19 years of follow-up, 255 men developed RCC. Cox proportional hazards models were utilized to estimate relative risks (RR) and 95% confidence intervals (CI). Despite a large range in intake, no association was observed between fruit, vegetables or antioxidant nutrients and RCC risk. For example, multivariate RRs and 95% CIs for the highest versus the lowest quartile of intake were 0.79 (0.55-1.14), 1.23 (0.85-1.79), 1.09 (0.74-1.60), 0.83 (0.57-1.21), 1.09 (0.73-1.64) and 0.99 (0.67-1.46) for fruit, vegetables, total carotenoids, total flavonoids, total vitamin E and vitamin C, respectively (all p values for trend > 0.05). Our results indicate that diet may not play a large role in the etiology of RCC in male smokers, although further examination of these associations in nonsmokers, women and diverse racial populations is warranted.

Serum insulin, glucose, indices of insulin resistance, and risk of prostate cancer

BACKGROUND

The mitogenic and growth-stimulatory effects of insulin-like growth factors appear to play a role in prostate carcinogenesis, yet any direct association of circulating insulin levels and risk of prostate cancer remains unclear.

METHODS

We investigated the relationship of the level of serum insulin, glucose, and surrogate indices of insulin resistance (ie, the molar ratio of insulin to glucose and the homeostasis model assessment of insulin resistance [HOMA-IR]) to the development of prostate cancer in a case-cohort study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of Finnish men. We studied 100 case subjects with incident prostate cancer and 400 noncase subjects without prostate cancer from the larger cohort. Fasting serum was collected 5-12 years before diagnosis. We determined insulin concentrations with a double-antibody immunochemiluminometric assay and glucose concentrations with a hexokinase assay. Multivariable logistic regression models estimated relative risks as odds ratios (ORs), and all statistical tests were two-sided.

RESULTS

Insulin concentrations in fasting serum that was collected on average 9.2 years before diagnosis among case subjects were 8% higher than among noncase subjects, and the molar ratio of insulin to glucose and HOMA-IR were 10% and 6% higher, respectively, but these differences were not statistically significant. Among subjects in the second through fourth insulin quartiles, compared with those in the first quartile, increased insulin levels were associated with statistically significantly increased risks of prostate cancer (OR = 1.50, 95% confidence interval [CI] = 0.75 to 3.03; OR = 1.75, 95% CI = 0.86 to 3.56; and OR = 2.55, 95% CI = 1.18 to 5.51; for the second through fourth insulin quartiles, respectively; P(trend) = .02). A similar pattern was observed with the HOMA-IR (OR = 2.10, 95% CI = 1.03 to 4.26; P(trend) = .02) for the highest vs lowest quartiles. Risk varied inconsistently with glucose concentration (P(trend) = .38). A stronger association between insulin level and prostate cancer risk was observed among leaner men and among men who were less physically active at work. Crude prostate cancer incidence was 154 prostate cancers per 100 000 person-years in the lowest quartile of fasting serum insulin vs 394 prostate cancers per 100 000 person-years in the highest quartile.

CONCLUSION

Elevated fasting levels of serum insulin (but not glucose) within the normal range appear to be associated with a higher risk of prostate cancer.

Vitamin E intake and risk of esophageal and gastric cancers in the NIH-AARP Diet and Health Study

We investigated the association of dietary alpha-tocopherol, gamma-tocopherol and supplemental vitamin E intake with the risk of esophageal squamous cell carcinoma (n = 158), esophageal adenocarcinoma (n = 382), gastric cardia adenocarcinoma (n = 320) and gastric noncardia adenocarcinoma (GNCA; n = 327) in the NIH-AARP Diet and Health Study, a cohort of approximately 500,000 people. Data on dietary and supplemental vitamin E intake were collected using a validated questionnaire at baseline and were analyzed using Cox regression models. Intakes were analyzed as continuous variables and as quartiles. For dietary alpha-tocopherol, we found some evidence of association with decreased esophageal squamous cell carcinoma and increased esophageal adenocarcinoma risk in the continuous analyses, with adjusted hazard ratios and 95% confidence intervals of 0.90 (0.81-0.99) and 1.05 (1.00-1.11), respectively, per 1.17 mg (half the interquartile range) increased intake. However, in quartile analyses, the p value for trend was nonsignificant for both these cancers. There was no association between dietary alpha-tocopherol and gastric cardia adenocarcinoma or GNCA. We observed no statistically significant associations with gamma-tocopherol. For supplemental vitamin E, the results were mainly null, except for a significantly lower risk of GNCA with higher doses of supplemental vitamin E. An increase of 71 mg/day (half the interquartile range) in supplemental vitamin E had an hazard ratio (95% confidence interval) of 0.92 (0.85-1.00) and the p value for trend in the quartile analysis was 0.015.

Association of variants in two vitamin e transport genes with circulating vitamin e concentrations and prostate cancer risk

Significant reductions in prostate cancer incidence and mortality were observed in men randomized to receive 50 mg supplemental vitamin E (alpha-tocopherol) per day in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. We hypothesized that variation in key vitamin E transport genes might directly affect prostate cancer risk or modify the effects of vitamin E supplementation. Associations between prostate cancer risk and 13 polymorphisms in two genes, TTPA and SEC14L2, were examined in 982 incident prostate cancer cases and 851 controls drawn from the ATBC Study. There was no association between the genetic variants and prostate cancer risk. Significant interactions were observed, however, between two variants in SEC14L2 (IVS11+931A>G and IVS11-896A>T) and the trial alpha-tocopherol supplement such that vitamin E supplementation reduced prostate cancer risk among men who were homozygous for either common allele [odds ratios (OR) and 95% confidence intervals (95% CI), 0.52 (0.30-0.90) and 0.64 (0.46-0.88), respectively] and nonsignificantly increased risk among those who carried one or two copies of either variant allele [ORs and 95% CIs, 1.27 (0.90-1.79) and 1.21 (0.96-1.52), respectively; both P for interaction < 0.05]. Genotype-phenotype analyses revealed significant but modest differences in baseline circulating concentrations of alpha-tocopherol and serum responses to the vitamin E supplementation for several polymorphisms. This study shows that genetic variation in TTPA and SEC14L2 is associated with serum alpha-tocopherol but does not have a direct effect on prostate cancer. Our results do, however, suggest that polymorphisms in SEC14L2 may modify the effect of vitamin supplementation regimens on prostate cancer risk.

Education and risk of cancer in a large cohort of men and women in the United States

BACKGROUND

Education inequalities in cancer incidence have long been noted. It is not clear, however, whether such inequalities persist in the United States, especially for less common malignancies and after adjustment for individual risk factors.

METHODOLOGY/PRINCIPAL FINDINGS

Within the NIH-AARP Diet and Health Study, we examined the association between education and the risk of developing cancers in a prospective cohort of 498,455 participants who were 50-71 year old and without cancer at enrollment in 1995/96. During a maximum 8.2 years of follow-up we identified 40,443 cancers in men and 18,367 in women. In age-adjusted models, the least educated men (

CONCLUSIONS/SIGNIFICANCE

We found a higher risk of malignant disease, particularly smoking- related cancers, among those in the lowest educational attainment category. Only some of the educational gradient is attributable to smoking. The persistence of substantial education inequalities in cancer incidence poses a challenge for etiologic research and public health policy.

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Key Words Collapse

MESH Headings

• Aged
• Animals
• Educational Status
• Female
• Humans
• Male
• Middle Aged
• Neoplasms/epidemiology
• Prospective Studies
• Risk Factors
• Smoking
• United States/epidemiology

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Grants

• Intramural NIH HHS

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Affiliation(s)

Traci Mouw Division of Epidemiology, Public Health & Primary Care, Faculty of Medicine, Imperial College London, London, United Kingdom
Annemarie Koster Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States of America Faculty of Health, Medicine and Life Sciences, Universiteit Maastricht, Maastricht, The Netherlands
Margaret E. Wright Department of Pathology, University of Illinois at Chicago, Chicago, Illinois, United States of America
Madeleine M. Blank Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
Steven C. Moore Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
Albert Hollenbeck AARP, Washington, D. C., United States of America
Arthur Schatzkin Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America

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Intakes of fruit, vegetables, and specific botanical groups in relation to lung cancer risk in the NIH-AARP Diet and Health Study

Increased fruit and vegetable consumption may protect against lung cancer, although epidemiologic findings are inconclusive. The authors prospectively examined associations between lung cancer risk and intakes of fruit, vegetables, and botanical subgroups in 472,081 participants aged 50-71 years in the National Institutes of Health (NIH)-AARP Diet and Health Study. Diet was assessed at baseline (1995-1996) with a 124-item dietary questionnaire. A total of 6,035 incident lung cancer cases were identified between 1995 and 2003. Total fruit and vegetable intake was unrelated to lung cancer risk in both men and women. Higher consumption of several botanical subgroups, however, was significantly inversely associated with risk, but only in men. For example, the relative risks of lung cancer among men in the highest versus lowest quintiles of intake of rosaceae, convolvulaceae, and umbelliferae were 0.82 (95% confidence interval (CI): 0.73, 0.91), 0.86 (95% CI: 0.75, 0.96), and 0.86 (95% CI: 0.78, 0.96), respectively; corresponding relative risks in women were 0.97 (95% CI: 0.85, 1.12), 0.95 (95% CI: 0.83, 1.09), and 0.92 (95% CI: 0.80, 1.06). These results provide support for a protective role of specific botanical subgroups of fruits and vegetables in lung cancer prevention in men, although the findings could also be due to residual confounding by smoking or chance.

Sequential concentration of bacteria and viruses from marine waters using a dual membrane system

The ability to rapidly and effectively concentrate diverse microbes is an essential component for monitoring water quality at recreational beaches. The purpose of this study was to develop a 0.45 microm pore size dual membrane system, which can sequentially concentrate both viruses and bacteria. The top PVDF membrane was used to filter bacteria by physical straining while the bottom HA membrane retained viruses through adsorption. The recovery of this system was assessed using test organisms: enterococci and somatic coliphage. Volumes of 100 to 400 mL of unspiked and sewage-spiked beach water were filtered through both types of membranes. The PVDF membrane recovered statistically equivalent amounts of enterococci when compared to traditional membranes. All of the coliphage passed through the PVDF membrane, while 22% passed through the HA membrane. Increasing the volume from 100 to 400 mL did not significantly influence recoveries. Up to 35% of coliphage was eluted from the bottom membrane using beef extract solution. Rinsing bottom membranes with 0.5 mmol L(-1) H(2)S0(4) was found to deactivate somatic coliphage. This research demonstrates the potential of using a dual membrane adsorption system for the concentration of both bacteria and viruses from recreational beaches. A proposed bi-layer filtration system can be designed for simultaneous bacteria and virus filtration. Future experiments should focus on measurements utilizing additional bacteria and viruses.

Multivitamin use and risk of prostate cancer in the National Institutes of Health-AARP Diet and Health Study

BACKGROUND

Multivitamin supplements are used by millions of Americans because of their potential health benefits, but the relationship between multivitamin use and prostate cancer is unclear.

METHODS

We prospectively investigated the association between multivitamin use and risk of prostate cancer (localized, advanced, and fatal) in 295,344 men enrolled in the National Institutes of Health (NIH)-AARP Diet and Health Study who were cancer free at enrollment in 1995 and 1996. During 5 years of follow-up, 10,241 participants were diagnosed with incident prostate cancer, including 8765 localized and 1476 advanced cancers. In a separate mortality analysis with 6 years of follow-up, 179 cases of fatal prostate cancer were ascertained. Multivitamin use was assessed at baseline as part of a self-administered, mailed food-frequency questionnaire. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated by use of Cox proportional hazards regression, adjusted for established or suspected prostate cancer risk factors.

RESULTS

No association was observed between multivitamin use and risk of localized prostate cancer. However, we found an increased risk of advanced and fatal prostate cancers (RR = 1.32, 95% CI = 1.04 to 1.67 and RR = 1.98, 95% CI = 1.07 to 3.66, respectively) among men reporting excessive use of multivitamins (more than seven times per week) when compared with never users. The incidence rates per 100,000 person-years for advanced and fatal prostate cancers for those who took a multivitamin more than seven times per week were 143.8 and 18.9, respectively, compared with 113.4 and 11.4 in never users. The positive associations with excessive multivitamin use were strongest in men with a family history of prostate cancer or who took individual micronutrient supplements, including selenium, beta-carotene, or zinc.

CONCLUSION

These results suggest that regular multivitamin use is not associated with the risk of early or localized prostate cancer. The possibility that men taking high levels of multivitamins along with other supplements have increased risk of advanced and fatal prostate cancers is of concern and merits further evaluation.

A prospective investigation of height and prostate cancer risk

Greater adult height, which reflects a combination of early nutrition, exposure to androgens, growth hormones, and other factors during growth and development, as well as heredity, has been associated with increased prostate cancer risk in several observational studies, but findings have been inconsistent. We examined this relationship in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. At baseline, 29,119 Finnish male smokers 50 to 69 years old had height and weight measured by trained personnel, provided information on demographic, smoking, medical, and other characteristics, and completed an extensive diet history questionnaire. A total of 1,346 incident prostate cancer cases were identified during a follow-up period of up to 17.4 years (median, 14.1 years). In age-adjusted Cox proportional hazards models, the hazard ratios and 95% confidence intervals for prostate cancer according to increasing quintiles of height [<or=168, 169-171, 172-175, 176-178, and >178 cm] were 1.00 (reference), 1.11 (0.93-1.32), 1.11 (0.95-1.31), 1.30 (1.01-1.55), and 1.14 (0.96-1.35); P(trend) = 0.04. In analyses stratified by disease stage (available for 916 cases), a strong dose-response relationship was observed between greater height and advanced, but not earlier-stage, disease [tumor-node-metastasis stage III-IV, hazard ratio and 95% confidence interval for increasing quintiles of height: 1.77 (1.18-2.65), 1.82 (1.25-2.65), 1.93 (1.29-2.90), and 2.02 (1.37-2.97); P(trend) = 0.0008, P(interaction) = 0.002]. Our study provides additional evidence that increased height is a risk factor for prostate cancer and suggests that taller men are particularly susceptible to advanced disease.

Supplemental and Dietary Vitamin E Intakes and Risk of Prostate Cancer in a Large Prospective Study

Supplemental vitamin E (alpha-tocopherol) has been linked to lower prostate cancer incidence in one randomized trial and several, although not all, observational studies. The evidence regarding dietary intake of individual vitamin E isoforms and prostate cancer is limited and inconclusive, however. We prospectively examined the relations of supplemental vitamin E and dietary intakes of alpha-, beta-, gamma-, and delta- tocopherols to prostate cancer risk among 295,344 men, ages 50 to 71 years and cancer-free at enrollment in 1995 to 1996, in the NIH-AARP Diet and Health Study. At baseline, participants completed a questionnaire that captured information on diet, supplement use, and other factors. Proportional hazards models were used to estimate relative risks (RR) and 95% confidence intervals (95% CI) of prostate cancer. During 5 years of follow-up, 10,241 incident prostate cancers were identified. Supplemental vitamin E intake was not related to prostate cancer risk (for >0-99, 100-199, 200-399, 400-799, and > or = 800 IU/d versus never use: RR, 0.97, 0.89, 1.03, 0.99, and 0.97 (95% CI, 0.87-1.07) respectively; Ptrend = 0.90). However, dietary gamma-tocopherol, the most commonly consumed form of vitamin E in the United States, was significantly inversely related to the risk of advanced prostate cancer (for highest versus lowest quintile: RR, 0.68; 95% CI, 0.56-0.84; Ptrend = 0.001). These results suggest that supplemental vitamin E does not protect against prostate cancer, but that increased consumption of gamma-tocopherol from foods is associated with a reduced risk of clinically relevant disease. The potential benefit of gamma-tocopherol for prostate cancer prevention deserves further attention.

Serum and Dietary Vitamin E in Relation to Prostate Cancer Risk

Alpha-tocopherol supplementation (50 mg daily for 5-8 years) reduced prostate cancer incidence by 32% in the alpha-Tocopherol, beta-Carotene Cancer Prevention Study. We investigated whether serum alpha-tocopherol or intake of vitamin E (eight tocopherols and tocotrienols) was associated with prostate cancer risk with up to 19 years of follow-up in the alpha-Tocopherol, beta-Carotene Cancer Prevention Study cohort. Of the 29,133 Finnish male smokers, ages 50 to 69 years recruited into the study, 1,732 were diagnosed with incident prostate cancer between 1985 and 2004. Baseline serum alpha-tocopherol was measured by high-performance liquid chromatography and the components of vitamin E intake were estimated based on a 276-item food frequency questionnaire and food chemistry analyses. Proportional hazard models were used to determine multivariate-adjusted relative risks (RR) and 95% confidence intervals (95% CI). Higher serum alpha-tocopherol was associated with reduced risk of prostate cancer (RR, 0.80; 95% CI, 0.66-0.96 for highest versus lowest quintile; Ptrend = 0.03) and was strongly and inversely related to the risk of developing advanced disease (RR, 0.56; 95% CI, 0.36-0.85; Ptrend = 0.002). The inverse serum alpha-tocopherol-prostate cancer association was greater among those who were supplemented with either alpha-tocopherol or beta-carotene during the trial. There were no associations between prostate cancer and the individual dietary tocopherols and tocotrienols. In summary, higher prediagnostic serum concentrations of alpha-tocopherol, but not dietary vitamin E, was associated with lower risk of developing prostate cancer, particularly advanced prostate cancer.

Multivitamin Use and Risk of Prostate Cancer in the National Institutes of Health-AARP Diet and Health Study

BACKGROUND

Multivitamin supplements are used by millions of Americans because of their potential health benefits, but the relationship between multivitamin use and prostate cancer is unclear.

METHODS

We prospectively investigated the association between multivitamin use and risk of prostate cancer (localized, advanced, and fatal) in 295,344 men enrolled in the National Institutes of Health (NIH)-AARP Diet and Health Study who were cancer free at enrollment in 1995 and 1996. During 5 years of follow-up, 10,241 participants were diagnosed with incident prostate cancer, including 8765 localized and 1476 advanced cancers. In a separate mortality analysis with 6 years of follow-up, 179 cases of fatal prostate cancer were ascertained. Multivitamin use was assessed at baseline as part of a self-administered, mailed food-frequency questionnaire. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated by use of Cox proportional hazards regression, adjusted for established or suspected prostate cancer risk factors.

RESULTS

No association was observed between multivitamin use and risk of localized prostate cancer. However, we found an increased risk of advanced and fatal prostate cancers (RR = 1.32, 95% CI = 1.04 to 1.67 and RR = 1.98, 95% CI = 1.07 to 3.66, respectively) among men reporting excessive use of multivitamins (more than seven times per week) when compared with never users. The incidence rates per 100,000 person-years for advanced and fatal prostate cancers for those who took a multivitamin more than seven times per week were 143.8 and 18.9, respectively, compared with 113.4 and 11.4 in never users. The positive associations with excessive multivitamin use were strongest in men with a family history of prostate cancer or who took individual micronutrient supplements, including selenium, beta-carotene, or zinc.

CONCLUSION

These results suggest that regular multivitamin use is not associated with the risk of early or localized prostate cancer. The possibility that men taking high levels of multivitamins along with other supplements have increased risk of advanced and fatal prostate cancers is of concern and merits further evaluation.

History of diabetes mellitus and subsequent prostate cancer risk in the NIH-AARP Diet and Health Study

OBJECTIVE

A history of diabetes has been hypothesized to decrease prostate cancer risk, but studies have not always considered confounding or effect modification by dietary or lifestyle factors.

METHODS

We examined the association between diabetes history and subsequent prostate cancer risk in 328,316 men enrolled in the NIH-AARP Diet and Health Study. Participants were ages 50-71 years and without a prostate cancer diagnosis at baseline in 1995. A prior history of physician-diagnosed diabetes was assessed using a self-administered mailed questionnaire. Cases of prostate cancer were ascertained by matching the cohort to state cancer registries. Multivariable relative risks (RR) and 95% confidence intervals (CI) of prostate cancer were estimated using Cox regression.

RESULTS

During 5 years and 1,432,676 person-years of follow-up, 11,193 prostate cancer cases were ascertained. The age-adjusted and multivariable RRs of prostate cancer comparing men with diabetes to those without diabetes were 0.69 (95% CI=0.64, 0.74) and 0.71 (95% CI=0.66, 0.76), respectively, indicating no important confounding. The inverse association between diabetes and prostate cancer was particularly strong among men in the highest category of routine physical activity at work or home (RR=0.41; 95% CI=0.23, 0.74; p value for test of interaction = 0.03). Findings were similar for organ-confined and advanced prostate cancer.

CONCLUSION

Results from this large prospective study suggest that a history of diabetes is associated with a decreased risk of prostate cancer. The relationship strengthened with high levels of routine physical activity. Because increased physical activity is associated with lower circulating levels of insulin and testosterone, our findings support a role of hypoinsulinemia and low androgenicity linking diabetes to decreased prostate cancer risk.

Prospective study of adiposity and weight change in relation to prostate cancer incidence and mortality

BACKGROUND

Adiposity has been linked inconsistently with prostate cancer, and few studies have evaluated whether such associations vary by disease aggressiveness.

METHODS

The authors prospectively examined body mass index (BMI) and adult weight change in relation to prostate cancer incidence and mortality in 287,760 men ages 50 years to 71 years at enrollment (1995-1996) in the National Institutes of Health-AARP Diet and Health Study. At baseline, participants completed questionnaires regarding height, weight, and cancer screening practices, including digital rectal examinations and prostate-specific antigen tests. Cox regression analysis was used to calculate relative risks (RR) and 95% confidence intervals (95% CIs).

RESULTS

In total, 9986 incident prostate cancers were identified during 5 years of follow-up, and 173 prostate cancer deaths were ascertained during 6 years of follow-up. In multivariate models, higher baseline BMI was associated with significantly reduced total prostate cancer incidence, largely because of the relationship with localized tumors (for men in the highest BMI category [>or=40 kg/m(2)] vs men in the lowest BMI category [<25 kg/m(2)]: RR, 0.67; 95% CI, 0.50-0.89; P = .0006). Conversely, a significant elevation in prostate cancer mortality was observed at higher BMI levels (BMI <25 kg/m(2): RR, 1.0 [referent group]; BMI 25-29.9 kg/m(2): RR, 1.25; 95% CI, 0.87-1.80; BMI 30-34.9 kg/m(2): RR, 1.46; 95% CI, 0.92-2.33; and BMI >or=35 kg/m(2): RR, 2.12; 95% CI, 1.08-4.15; P = .02). Adult weight gain from age 18 years to baseline also was associated positively with fatal prostate cancer (P = .009), but not with incident disease.

CONCLUSIONS

Although adiposity was not related positively to prostate cancer incidence, higher BMI and adult weight gain increased the risk of dying from prostate cancer.

Effects of α-tocopherol and β-carotene supplementation on upper aerodigestive tract cancers in a large, randomized controlled trial

BACKGROUND

Although smoking and alcohol consumption are the major risk factors for upper aerodigestive tract cancers, observational studies indicate a protective role for fruits, vegetables, and antioxidant nutrients.

METHODS

The authors examined whether daily supplementation with 50 mg dl alpha-tocopheryl acetate and/or 20 mg beta-carotene reduced the incidence of or mortality from oral/pharyngeal, esophageal, and laryngeal cancers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) study, a double-blind, placebo-controlled primary prevention trial conducted in southwestern Finland. A total of 29,133 male smokers, aged 50-69 years and free of cancer at baseline, were randomized in a 2 x 2 factorial design to the supplementation regimen for 5-8 years (median, 6.1 years). Incident cancers of the oral cavity and pharynx (n = 65), esophagus (n = 24), and larynx (n = 56) were identified through the Finnish Cancer Registry. Intervention effects were assessed using survival analysis and proportional hazards models.

RESULTS

There was no effect of either agent on the overall incidence of any upper aerodigestive tract cancer. For larynx, however, exploratory subgroup analyses were suggestive of a protective effect of beta-carotene supplementation on the incidence of early stage malignancies (stage I, relative risk [RR], 0.28, 95% confidence interval [CI]: 0.10-0.75). Neither agent affected mortality from these neoplasms.

CONCLUSIONS

The results do not provide support for a protective effect of vitamin E or beta-carotene supplementation on upper aerodigestive tract cancers, although beta-carotene supplementation may impact the incidence of some subtypes of laryngeal tumors.

Higher baseline serum concentrations of vitamin E are associated with lower total and cause-specific mortality in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study

BACKGROUND

A meta-analysis of 19 trials suggested a small increase in the risk of all-cause mortality with high-dose vitamin E supplementation. Little is known, however, about the relation between mortality and circulating concentrations of vitamin E resulting from dietary intake, low-dose supplementation, or both.

OBJECTIVE

We examined whether baseline serum alpha-tocopherol concentrations are associated with total and cause-specific mortality.

DESIGN

A prospective cohort study of 29 092 Finnish male smokers aged 50-69 y who participated in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study was carried out. Fasting serum alpha-tocopherol was measured at baseline by using HPLC. Only 10% of participants reported vitamin E supplement use at baseline, and thus serum concentrations of vitamin E mainly reflected dietary intake and other host factors. Risks of total and cause-specific mortality were estimated by using proportional hazards models.

RESULTS

During up to 19 y of follow-up, 13 380 deaths (including 4518 and 5776 due to cancer and cardiovascular disease, respectively) were identified. Men in the higher quintiles of serum alpha-tocopherol had significantly lower risks of total and cause-specific mortality than did those in the lowest quintile [relative risk (RR) = 0.82 (95% CI: 0.78, 0.86) for total mortality and 0.79 (0.72, 0.86), 0.81 (0.75, 0.88), and 0.70 (0.63, 0.79) for deaths due to cancer, cardiovascular disease, and other causes, respectively; P for trend for all < 0.0001]. Cubic regression spline analysis of continuous serum alpha-tocopherol values indicated greater risk reductions with increasing concentrations up to approximately 13-14 mg/L, after which no further benefit was noted.

CONCLUSION

Higher circulating concentrations of alpha-tocopherol within the normal range are associated with significantly lower total and cause-specific mortality in older male smokers.

Direct cancer tissue proteomics: a method to identify candidate cancer biomarkers from formalin-fixed paraffin-embedded archival tissues

Successful treatment of multiple cancer types requires early detection and identification of reliable biomarkers present in specific cancer tissues. To test the feasibility of identifying proteins from archival cancer tissues, we have developed a methodology, termed direct tissue proteomics (DTP), which can be used to identify proteins directly from formalin-fixed paraffin-embedded prostate cancer tissue samples. Using minute prostate biopsy sections, we demonstrate the identification of 428 prostate-expressed proteins using the shotgun method. Because the DTP method is not quantitative, we employed the absolute quantification method and demonstrate picogram level quantification of prostate-specific antigen. In depth bioinformatics analysis of these expressed proteins affords the categorization of metabolic pathways that may be important for distinct stages of prostate carcinogenesis. Furthermore, we validate Wnt-3 as an upregulated protein in cancerous prostate cells by immunohistochemistry. We propose that this general strategy provides a roadmap for successful identification of critical molecular targets of multiple cancer types.

Estimated urine pH and bladder cancer risk in a cohort of male smokers (Finland)

OBJECTIVE

Low urine pH may be an important risk factor for bladder cancer, although few studies have evaluated this association. We examined the relationship between estimated renal net acid excretion (NAE), an indirect measure of urine pH based on nutrient intake and anthropometry, and bladder cancer risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study.

METHODS

At baseline, 27,096 male smokers 50-69 years old completed a dietary questionnaire that assessed usual frequency of consumption and portion sizes for the previous 12 months, had height and weight measured, and provided a history of smoking. A total of 446 incident bladder cancer cases were identified during up to 17.4 years of follow-up.

RESULTS

In multivariate proportional hazards models, the relative risk (RR) for bladder cancer was 1.15 (95% confidence interval (CI)=0.86-1.55) for individuals in the highest (i.e., most acidic) versus the lowest (i.e., least acidic) NAE quintile (p=0.38). Among men who smoked for more than 45 years, there was a suggestion of increased risk with higher NAE levels (RR=1.72, 95% CI=0.96-3.10, p=0.08).

CONCLUSIONS

These findings do not indicate that urine pH is a major risk factor for bladder cancer, although certain subsets of individuals may be at increased risk.

Serum -Tocopherol and -Tocopherol in Relation to Prostate Cancer Risk in a Prospective Study

The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study demonstrated a 32% reduction in prostate cancer incidence in response to daily alpha-tocopherol supplementation. We examined baseline serum concentrations of alpha-tocopherol and gamma-tocopherol to compare their respective associations with prostate cancer risk. From the ATBC Study cohort of 29 133 Finnish men, 50-69 years old, we randomly selected 100 incident prostate cancer case patients and matched 200 control subjects. Odds ratios and 95% confidence intervals (CIs) were estimated for the serum tocopherols (measured by high-performance liquid chromatography) using logistic regression models. All P values were two-sided. Odds ratios for the highest versus the lowest tertiles were 0.49 (95% CI = 0.24 to 1.01, P(trend) = .05) for alpha-tocopherol and 0.57 (95% CI = 0.31 to 1.06, P(trend) = .08) for gamma-tocopherol. Further analyses indicated that the association of high serum tocopherols with low prostate cancer risk was stronger in the alpha-tocopherol-supplemented group than in those not receiving alpha-tocopherol. Participants with higher circulating concentrations of the major vitamin E fractions, alpha-tocopherol and gamma-tocopherol, had similarly lower prostate cancer risk.

Arsenic concentrations in prediagnostic toenails and the risk of bladder cancer in a cohort study of male smokers

At high concentrations, inorganic arsenic can cause bladder cancer in humans. However, it is unclear whether low exposure to inorganic arsenic in drinking water (<100 microg/liter) is related to bladder cancer risk. No study has been known to use biomarkers to assess the relation between individual arsenic exposure and bladder cancer risk. Toenail samples provide an integrated measure of internal arsenic exposure and reflect long-term exposure. The authors examined the relation between toenail arsenic levels and bladder cancer risk among participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, a cohort of Finnish male smokers aged 50-69 years. Data for 280 incident bladder cancer cases, identified between baseline (1985-1988) and April 1999, were available for analysis. One control was matched to each case on the basis of age, toenail collection date, intervention group, and smoking duration. Arsenic levels in toenail samples were determined by using neutron activation analysis. Logistic regression analyses were performed to estimate odds ratios. Arsenic toenail concentrations in this Finnish study were similar to those reported in US studies (range: 0.02-17.5 microg/g). The authors observed no association between inorganic arsenic concentration and bladder cancer risk (odds ratio = 1.13, 95% confidence interval: 0.70, 1.81 for the highest vs. lowest quartile). These findings suggest that low-level arsenic exposure is unlikely to explain a substantial excess risk of bladder cancer.

Development of a comprehensive dietary antioxidant index and application to lung cancer risk in a cohort of male smokers

In many observational studies, a higher intake of individual antioxidants is inversely associated with lung cancer risk. Data from in vitro and animal experiments suggest that there are biochemical interactions among antioxidant nutrients; therefore, consideration of multiple antioxidants simultaneously may be important in terms of risk estimation. The authors constructed a dietary antioxidant index and evaluated its ability to predict lung cancer risk within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. At baseline (1985-1988), 27,111 Finnish male smokers aged 50-69 years completed a dietary questionnaire that assessed usual frequency of consumption and portion sizes for the previous 12 months. A total of 1,787 incident cases of lung cancer were identified during a follow-up period of up to 14.4 years (1985-1999). Principal components analyses were individually applied to the carotenoid, flavonoid, and vitamin E nutrient groups, and summation of retained principal component scores, plus selenium and vitamin C, yielded the composite antioxidant index. In multivariate proportional hazards models, the relative risks for lung cancer according to increasing quintiles of the antioxidant index were 1.00 (referent), 1.00 (95% confidence interval (CI): 0.87, 1.14), 0.91 (95% CI: 0.79, 1.05), 0.79 (95% CI: 0.68, 0.92), and 0.84 (95% CI: 0.72, 0.98) (p for trend = 0.002). These findings support the hypothesis that a combination of dietary antioxidants reduces lung cancer risk in male smokers.

Dietary carotenoids, vegetables, and lung cancer risk in women: the Missouri women's health study (United States)

OBJECTIVE

To examine the effect of specific dietary carotenoids and their primary plant food sources on lung cancer risk in a population-based case-control study of women.

METHODS

Data were available for 587 incident primary lung cancer cases and 624 controls frequency matched to cases based on age. A modified version of the 100-item NCI-Block food-frequency questionnaire was used to obtain information concerning usual diet 2-3 years prior to interview.

RESULTS

In models adjusted for age, total calorie intake, pack-years of smoking, and education, beta-carotene, beta-cryptoxanthin, lutein + zeaxanthin, and total carotenoid intake were each associated with a significantly lower risk of lung cancer. Several vegetable groups were predictive of lower lung cancer risk, particularly the frequency of total vegetable intake. Individual and total carotenoids were no longer significantly associated with lower lung cancer risk in models adjusted for total vegetable intake. However, total vegetable intake remained significantly inversely associated with risk in models adjusted for total carotenoids.

CONCLUSIONS

These results indicate that consumption of a wide variety of vegetables has a greater bearing on lung cancer risk in a population of smoking and nonsmoking women than intake of any specific carotenoid or total carotenoids.

Ongoing trials of immune-based therapies for HIV infection in adults

Highly active antiretroviral therapy (HAART) can significantly alter the clinical course of patients infected with HIV. Unfortunately, effective lifelong HAART may not be a practical or achievable goal because of toxicities, cost, development of viral resistance and patient compliance issues. Immune-based therapies (IBTs) that target the host immune system may serve as rational additions to our current antiretroviral strategies. Investigations into IL-2 have culminated in two large Phase III clinical trials. Multiple therapeutic vaccine candidates are in various phases of investigation. In addition, gene therapy has been proposed as a potential treatment for HIV and Phase I trials are ongoing. Although IBTs are being investigated on many fronts, they remain difficult to study due to a lack of validated surrogate end points.