Background: Volatile organic compounds (VOCs) are major components of air pollution and tobacco smoke, two known risk factors for cardiovascular diseases. VOCs are ubiquitous in the environment and originate from a wide range of sources, including the burning of biomass, fossil fuels, and consumer products. Direct evidence for associations between specific VOCs and ischemic heart disease (IHD) mortality in the general population is scarce. Methods: In a case-cohort study (stratified by age groups, sex, residence, and tobacco smoking), nested within the population-based Golestan cohort study (n = 50,045, 40–75 years, 58% women, enrollment: 2004–2008) in northeastern Iran, we measured urinary concentrations of 20 smoking-related VOC biomarkers using ultra high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. We calculated hazard ratio (HR) and 95% confidence interval (CI) for their associations with IHD mortality during follow-up to 2018, using Cox regression models adjusted for age, ethnicity, education, marital status, body mass index, physical activity, wealth, and urinary cotinine. Results: There were 575 non-cases from random subcohort and 601 participants who died from IHD, mean (standard deviation) age, 58.2 (9.3) years, with a median of 8.4 years follow-up. Significant associations [3rd vs. 1st tertile, HR (95% CI), P for trend] were observed between biomarkers of acrylamide [1.68(1.05,2.69), 0.025], acrylonitrile [2.06(1.14,3.72), 0.058], acrolein [1.98(1.30,3.01), 0.003 and 2.44(1.43,4.18), 0.002], styrene/ethylbenzene [1.83(1.19,2.84), 0.007 and 1.44(1.01,2.07), 0.046], dimethylformamide/methylisocyanate [2.15(1.33,3.50), 0.001], and 1,3butadiene [2.35(1.52,3.63),<0.001] and IHD mortality. These associations were independent of tobacco smoking, and they were only present in the non-smoking subgroup. Conclusion: Our findings provide direct evidence for associations between exposure to several VOCs with widespread household and commercial use and IHD mortality many years after these exposures. These results highlight the importance of VOC exposure in the general population as a risk factor for cardiovascular diseases and underline the importance of bio-monitoring non-tobacco VOC exposure. © 2024

Background. Benzene is a known human carcinogen. Human exposure to benzene can be assessed by measuring trans, trans-muconic acid (MUCA) in urine. Golestan Province in northeastern Iran has been reported to have high incidence of esophageal cancer linked to the use of tobacco products. This manuscript evaluates the urinary MUCA concentrations among the participants of the Golestan Cohort Study (GCS).Methods. We analyzed MUCA concentration in 177 GCS participants' urine samples and performed nonparametric pairwise multiple comparisons to determine statistically significant difference among six different product use groups. Mixed effects model was fitted on 22 participants who exclusively smoked cigarette and 51 participants who were classified as nonusers. The urinary MUCA data were collected at the baseline and approximately five years later, and intraclass correlation coefficient (ICC) was calculated from the model.Results. Compared with nonusers, tobacco smoking was associated with higher urinary MUCA concentrations. Based on the nonparametric test of pairwise multiple comparisons, MUCA concentrations among participants who smoked combusted tobacco products were statistically significantly higher compared to nonusers. Urinary MUCA collected five years apart from the same individuals showed moderate reliability (ICC = 0.41), which was expected given the relatively short half-life (∼6 hrs) of MUCA.Conclusion. Our study revealed that tobacco smoke was positively associated with increased levels of urinary MUCA concentration, indicating that it is a significant source of benzene exposure among GCS participants.

BACKGROUND: Studying carcinogens in tobacco and non-tobacco sources may be key to understanding the pathogenesis and geographic distribution of esophageal cancer. METHODS: Golestan Cohort Study (GCS) has been conducted since 2004 in a region with high rates of esophageal squamous cell carcinoma (ESCC). For this nested study, the cases comprised of all incident cases by Jan 1, 2018; controls were matched to the case by age, sex, residence, time in cohort, and tobacco use. We measured urinary concentrations of 33 exposure biomarkers of nicotine, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and tobacco-specific nitrosamines (TSNAs). We used conditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (95%CI) for associations between the 90th versus the 10th percentiles of the biomarker concentrations and incident ESCC. RESULTS: Among individuals who did not currently use tobacco (148 cases/163 controls), two acrolein metabolites, two acrylonitrile metabolites, one propylene oxide metabolite and one 1,3-butadiene metabolite were significantly associated with incident ESCC (adjusted ORs between 1.8 and 4.3). Among tobacco users (57 cases/63 controls), metabolites of two other VOCs (styrene and xylene) were associated with ESCC (ORs= 6.2 and 9.0). In tobacco users, two TSNAs (NNN and N'-Nitrosoanatabine) were also associated with ESCC. Suggestive associations were seen with some PAHs (especially 2-hydroxynaphthalene) in non-users of tobacco products and other TSNAs in tobacco users. CONCLUSION: These novel associations based on individual-level data and samples collected many years before cancer diagnosis, from a population without occupational exposure, have important public health implications.

BACKGROUND: The epidemiological evidence regarding the carcinogenicity of nitrate and sodium in drinking water is limited, partly because measuring the exposure at the individual level is complex. Most studies have used nitrate in water supplies as a proxy for individual exposure, but dietary intakes and other factors may contribute to the exposure. The present study investigates the factors associated with urinary nitrate and sodium in a high-risk area for esophageal and gastric cancers. METHODS: For this cross-sectional study, we used data and samples collected in 2004-2008 during the enrollment phase of the Golestan Cohort Study from a random sample of 349 participants (300 individuals from 24 rural villages and 49 from the city of Gonbad), stratified by average water nitrate in their district, the source of drinking water, and the usual dietary intake of nitrate and sodium. Nitrate, sodium, and creatinine were measured in a spot urine sample collected at the time of interview. We used the provincial cancer registry data to calculate the cumulative incidence rates of esophageal and gastric cancers for each location through June 1, 2020, and used weighted partial Pearson correlation to compare the incidence rates with median urinary nitrate and sodium in each village or the city. RESULTS: Among 349 participants (mean age±SD: 50.7 ± 8.6 years), about half (n = 170) used groundwater for drinking, and the use of ground water was significantly more common in high-elevation locations (75.8%). The geometric mean of the creatinine-corrected urinary nitrate concentration was 68.3 mg/g cr (95%CI: 64.6,72.3), and the corresponding geometric mean for urinary sodium was 150.0 mmoL/g cr (95%CI: 139.6161.1). After adjusting for confounders, urinary nitrate was associated with being a woman, drinking groundwater, and living in high-elevation locations, but not with estimated dietary intake. Urinary sodium concentration was significantly associated with monthly precipitation at the time of sampling but not with elevation or drinking water source. There were significant positive correlations between both median urinary nitrate and sodium in each location and esophageal cancer incidence rates adjusted for sex and age (r = 0.65 and r = 0.58, respectively, p < 0.01), but not with gastric cancer incidence. CONCLUSION: In a rural population at high risk for esophageal and gastric cancers, nitrate excretion was associated with living at a higher elevation and using groundwater for drinking. The associations between nitrate and sodium excretion with esophageal cancer incidence warrant future investigation.

BACKGROUND: Recent reports of lead poisoning suggest that people who use opium may be exposed to high amounts of lead. Here, we investigate the association between opium use and blood lead levels (BLL) in a population-based cohort study. METHODS: In 2017, we studied a random sample of 410 people who currently (both within the past year and the past month) used opium and 104 who did not from participants of the Golestan Cohort Study in northeast Iran. Participants were stratified by sex and tobacco use history, completed a comprehensive opiate and tobacco use questionnaire and provided blood. BLL was measured by Lead Care® II Blood Lead Test Kit, validated by inductively coupled plasma triple quadrupole mass spectrometry. BLL was categorized as "<5 µg/dL", "elevated" (5-10 µg/dL), "high" (10-50 µg/dL), and "very high" (above 50 µg/dL). To assess the association between BLL categories and opiate use, route of consumption and weekly use, we used ordered logistic regression models, and report OR (odds ratio) and 95% CI (confidence interval) adjusted for age, sex, place of residence, education, occupation, household fuel type, and tobacco use. RESULTS: In the cohort, participants used only raw (teriak) or refined (shireh) opium, which were smoked (45%, n = 184), taken orally (46%, n = 189), or both (9%, n = 37), for a mean duration of 24.2 (standard deviation: 11.6) years. The median BLL was significantly higher in people who currently used opium (11.4 µg/dL; IQR: 5.2-23.4) compared with those who did not (2.3 µg/dL; IQR: 2.3-4.2), and the highest median BLL was seen in oral use (21.7 µg/dL; IQR: 12.1-34.1). The BLL was <5 µg/dL among 79.8% of people with no opiate use, compared with only 22.7% in those using opium. BLL was elevated in 21.7%, high in 50.5% and very high in 5.1% of people using opium. About 95% of those with oral (180/189) or dual use (35/37) and 55% (102/184) of those who smoked opium had levels of blood lead above 5 µg/dL. The OR for the association between any opium use and each unit of increase in BLL category was 10.5 (95%CI: 5.8-19.1), and oral use of opium was a very strong predictor of increasing BLL category (OR=74.1; 95%CI: 35.1-156.3). This odds ratio was 38.8 (95%CI: 15.9-95.1) for dual use and 4.9 (95%CI: 2.6-9.1) for opium smoking. There was an independent dose-response association between average weekly dose and BLL among people using opium, overall and when stratified by route of use. CONCLUSION: Our results indicate that regular use of lead-adulterated opium can expose individuals to high levels of lead, which may contribute to mortality and cancer risks associated with long-term opium use.

Biomarkers of tobacco exposure are known to be associated with disease risk but previous studies are limited in number and restricted to certain regions. We conducted a nested case–control study examining baseline levels and subsequent lung cancer incidence among current male exclusive cigarette smokers in the Golestan Cohort Study in Iran. We calculated geometric mean biomarker concentrations for 28 matched cases and 52 controls for the correlation of biomarker levels among controls and for adjusted odds’ ratios (ORs) for lung cancer incidence by biomarker concentration, accounting for demographic characteristics, smoking quantity and duration, and opium use. Lung cancer cases had higher average levels of most biomarkers including total nicotine equivalents (TNE-2), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and 3-hydroxyfluorene (3-FLU). Many biomarkers correlated highly with one another including TNE-2 with NNAL and N-Acetyl-S-(2-cyanoethyl)-L-cysteine (2CYEMA), and N-Acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine (t4HBEMA) with N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (3HMPMA) and N-Acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine (4HMBEMA). Lung cancer risk increased with concentration for several biomarkers, including TNE-2 (OR = 2.22, 95% CI = 1.03, 4.78) and NNN (OR = 2.44, 95% CI = 1.13, 5.27), and estimates were significant after further adjustment for demographic and smoking characteristics for 2CYEMA (OR = 2.17, 95% CI = 1.03, 4.55), N-Acetyl-S-(2-carbamoylethyl)-L-cysteine (2CAEMA) (OR = 2.14, 95% CI = 1.01, 4.55), and N-Acetyl-S-(2-hydroxypropyl)-L-cysteine (2HPMA) (OR = 2.85, 95% CI = 1.04, 7.81). Estimates were not significant with adjustment for opium use. Concentrations of many biomarkers were higher at the baseline for participants who subsequently developed lung cancer than among the matched controls. Odds of lung cancer were higher for several biomarkers including with adjustment for smoking exposure for some but not with adjustment for opium use. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

BACKGROUND: Exposure to polycyclic aromatic hydrocarbons (PAHs) is a risk factor for esophageal squamous cell carcinoma (ESCC) in high-incidence areas of China, Iran and Brazil, but PAH assessments have not been conducted in East Africa, another ESCC hot spot. OBJECTIVE: To evaluate demographic or lifestyle factors associated with the PAH biomarker concentrations in the study population, and whether PAH metabolite concentrations showed any associations with esophageal precancerous lesions. METHODS: We recruited a community-based sample of 289 asymptomatic adults from a rural area of Kenya and performed Lugol's chromoendoscopy to detect esophageal squamous dysplasia (ESD); participants completed a questionnaire and provided a spot urine specimen. We analyzed urine for seven hydroxylated metabolites of naphthalene, fluorene, phenanthrene, and pyrene at the U.S. National Center for Environmental Health, and compared creatinine-corrected PAH metabolite concentrations with questionnaire data and the presence of ESD. RESULTS: PAH metabolite concentrations among never tobacco users in these rural Kenya residents were 2.4-28.1 times higher than those reported from never tobacco users in Iran, Brazil and the USA. Female sex, cooking indoors, having no post-primary education, and age <50, but not tobacco use, were positively and significantly associated with PAH metabolite concentrations. Almost all participants used wood as cooking fuel. Nine participants had advanced ESD. Adjusted logistic regression showed a significant association between 2-hydroxynaphthalene (OR = 4.19, 95%CI: 1.01-17.47) and advanced ESD. All other PAH metabolites had positive but non-significant associations with advanced ESD. CONCLUSIONS: Urinary PAH metabolite concentrations among never tobacco users are markedly higher in this group from Kenya than in other populations and are associated with indoor cooking with wood on open, unvented stoves. These metabolite concentrations were also associated with the presence of advanced esophageal dysplasia. Our findings underline the importance of assessing alternative cooking conditions to reduce PAH exposure in this population.

Questionnaire data have linked contact with ruminants to the risk of esophageal squamous cell carcinoma (ESCC) in high-risk Asian populations. To better understand this observed association, we investigated exposure to two major zoonotic ruminant pathogens relative to ESCC risk. Using enzyme-linked immunosorbent assay, immunofluorescence assay, and Brucella microagglutination test assays, we measured immunoglobulin G anti-Coxiella burnetii and anti-Brucella spp. antibodies in patients with ESCC (n = 177) and population-based controls (n = 177) matched by age, gender, and residence area from the Golestan case-control study in Iran. We found a similarly high seroprevalence of C. burnetii in ESCC cases and controls (75% and 80%, respectively), and a similarly low seroprevalence of Brucella spp. (0% and 0.6%, respectively). While documenting a high exposure to one of two zoonotic ruminant infections, this exposure failed to explain the observed association of ruminant contact and ESCC risk in this high-risk population.

BACKGROUND: There is little information on human exposure to carcinogens and toxicants related to opiate use, alone or combined with tobacco. METHODS: Among male participants of the Golestan Cohort Study in Northeast Iran, we studied 28 never users of either opiates or tobacco, 33 exclusive cigarette smokers, 23 exclusive users of smoked opiates, and 30 opiate users who also smoked cigarettes (dual users; 21 smoked opiates and 9 ingested them). We quantified urinary concentrations of 39 exposure biomarkers: tobacco alkaloids, tobacco specific nitrosamines (TSNAs), polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs) and used decomposition to parse out the share of the biomarker concentrations explained by opiate use and nicotine dose. RESULTS: Dual users had the highest concentrations of all biomarkers, but exclusive cigarette smokers and exclusive opiate users had substantially higher concentrations of PAH and VOC biomarkers than never users. Decomposition analysis showed that opiate use contributed a larger part of the PAH concentrations than nicotine dose, and the sum of 2- and 3-hydroxyphenanthrene ( summation operator2,3-phe) resulted almost completely from opiate use. Two acrylamide metabolites, a 1,3-butadiene metabolite, and a dimethylformamide metabolite were more strongly explained by opiate use. Acrylamide metabolites and summation operator2,3-phe were significantly higher in opiate smokers than opiate eaters; other biomarkers did not vary by the route of opiate intake. CONCLUSION: Both cigarette smokers and opiate users (by smoking or ingestion) were exposed to many toxicants and carcinogens. IMPACT: This high exposure, particularly among dual opiates and cigarette users can have substantial global public health impact.

BACKGROUND: How carcinogen exposure varies across users of different, particularly non-cigarette, tobacco products remains poorly understood. METHODS: We randomly selected 165 participants of Golestan Cohort Study from northeastern Iran: 60 never users of any tobacco, 35 exclusive cigarette, 40 exclusive (78% daily) waterpipe, and 30 exclusive smokeless tobacco (nass) users. We measured concentrations of 39 biomarkers of exposure in 4 chemical classes in baseline urine samples: tobacco alkaloids, tobacco-specific nitrosamines (TSNAs), polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs). We also quantified the same biomarkers in a second urine sample, obtained five years later, among continuing cigarette smokers and never tobacco users. RESULTS: Nass users had the highest concentrations of tobacco alkaloids. All tobacco users had elevated TSNA concentrations which correlated with nicotine dose. In both cigarette and waterpipe smokers, PAH and VOC biomarkers were higher than never tobacco users and nass users, and highly correlated with nicotine dose. PAH biomarkers of phenanthrene and pyrene, and two VOC metabolites (phenylmercapturic acid and phenylglyoxylic acid) were higher in waterpipe smokers than all other groups. PAH biomarkers among Golestan never tobacco users were comparable to those in U.S. cigarette smokers. All biomarkers had moderate to good correlations over five years, particularly in continuing cigarette smokers. CONCLUSION: We observed two patterns of exposure biomarkers that differentiated the use of the combustible products (cigarettes and waterpipe) from the smokeless product. Environmental exposure from non-tobacco sources appeared to contribute to the presence of high levels of PAH metabolites in the Golestan Cohort.

BACKGROUND: Consumption of mate, an infusion of the herb Ilex paraguariensis (yerba mate), is associated with increased risk of esophageal squamous cell carcinoma (ESCC), but the carcinogenic mechanism is unclear. Commercial brands of yerba mate contain high levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs), which are acquired during the traditional drying process. The purpose of this study was to characterize exposure to PAHs in mate drinkers over a wide range of mate consumption. METHODS: We recruited 244 adults who answered a questionnaire and collected a fasting spot urine specimen. We quantified urinary concentrations of seven PAH metabolites, and assessed associations between self-reported recent mate consumption and urinary PAH metabolites by multivariate regression. RESULTS: Recent mate consumption showed a significant dose-response association with 6 of 7 PAH metabolites in unadjusted models (p-for-trend <0.05). After adjustment for creatinine and potential confounders, concentrations of 2-naphthol, 1-hydroxyphenanthrene, and the sum of 2- and 3-hydroxyphenanthrene remained significantly associated with recent mate intake. The sum of the urinary concentrations of the phenanthrene metabolites was similar or higher among mate drinkers who did not smoke than among smokers who did not drink mate. CONCLUSIONS: Urinary concentrations of PAH metabolites were significantly associated with self-reported amount of recent mate intake, and drinking mate increased urinary concentrations of some PAH metabolites as much as smoking cigarettes. IMPACT: Drinking mate is a source of exposure to potentially carcinogenic PAHs, consistent with the hypothesis that the PAH content of mate may contribute to the increased risk of ESCC in mate drinkers.

To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases.

Analyses of genome-wide association study (GWAS) data have revealed that detectable genetic mosaicism involving large (>2 Mb) structural autosomal alterations occurs in a fraction of individuals. We present results for a set of 24,849 genotyped individuals (total GWAS set II [TGSII]) in whom 341 large autosomal abnormalities were observed in 168 (0.68%) individuals. Merging data from the new TGSII set with data from two prior reports (the Gene-Environment Association Studies and the total GWAS set I) generated a large dataset of 127,179 individuals; we then conducted a meta-analysis to investigate the patterns of detectable autosomal mosaicism (n = 1,315 events in 925 [0.73%] individuals). Restricting to events >2 Mb in size, we observed an increase in event frequency as event size decreased. The combined results underscore that the rate of detectable mosaicism increases with age (p value = 5.5 x 10(-31)) and is higher in men (p value = 0.002) but lower in participants of African ancestry (p value = 0.003). In a subset of 47 individuals from whom serial samples were collected up to 6 years apart, complex changes were noted over time and showed an overall increase in the proportion of mosaic cells as age increased. Our large combined sample allowed for a unique ability to characterize detectable genetic mosaicism involving large structural events and strengthens the emerging evidence of non-random erosion of the genome in the aging population.

OBJECTIVE: Studies of the fecal microbiome have implicated the gut microbiota in obesity, but few studies have examined the microbial diversity at other sites. The association between obesity and the upper gastrointestinal (UGI) microbial diversity was explored. METHODS: The UGI microbiome of 659 healthy Chinese adults with a measured body mass index (BMI) range of 15.0 to 35.7 was characterized using the 16S rRNA gene DNA microarray (HOMIM). RESULTS: In multivariate-adjusted models, alpha diversity was not associated with BMI. However, beta diversity, assessed by principal coordinate vectors generated from an unweighted UniFrac distance matrix of pairwise comparisons, was associated with BMI (third and fourth vectors, P = 0.01 and P = 0.03, respectively). Moreover, beta diversity, assessed by cluster membership (three clusters), was also associated with BMI; individuals in the first cluster [median BMI 22.35, odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.05-4.34] and second cluster [median BMI 22.55, OR = 0.26, 95% CI = 0.09-0.75] were significantly less likely to be obese (BMI ≥ 27.5) than those in the third cluster (median BMI 23.59). CONCLUSIONS: A beta-diversity metric of the UGI microbiome is associated with a four fold difference in obesity risk in this Asian population. Future studies should address whether the UGI microbiome plays a causal role in obesity.

Genome-wide association studies (GWAS) have mapped risk alleles for at least ten distinct cancers to a small region of 63,000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (ASSET) across six distinct cancers in 34,248 cases and 45,036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single nucleotide polymorphisms (SNPs): five in the TERT gene (region 1: rs7726159, P=2.10x10-39; region 3: rs2853677, P=3.30x10-36 and PConditional=2.36x10-8; region 4: rs2736098, P=3.87x10-12 and PConditional=5.19x10-6, region 5: rs13172201, P=0.041 and PConditional=2.04x10-6; and region 6: rs10069690, P=7.49x10-15 and PConditional=5.35x10-7) and one in the neighboring CLPTM1L gene (region 2: rs451360; P=1.90x10-18 and PConditional=7.06x10-16). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele specific effects on DNA methylation were seen for a subset of risk loci indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.

BACKGROUND: The human upper digestive tract microbial community (microbiota) is not well characterized and few studies have explored how it relates to human health. We examined the relationship between upper digestive tract microbiota and two cancer-predisposing states, serum pepsinogen I/pepsinogen II ratio (PGI/II; predictor of gastric cancer risk) and esophageal squamous dysplasia (ESD; the precursor lesion of esophageal squamous cell carcinoma; ESCC) in a cross-sectional design. METHODS: The Human Oral Microbe Identification Microarray was used to test for the presence of 272 bacterial species in 333 upper digestive tract samples from a Chinese cancer screening cohort. Serum PGI and PGII were determined by ELISA. ESD was determined by chromoendoscopy with biopsy. RESULTS: Lower microbial richness (number of bacterial genera per sample) was significantly associated with lower PGI/II ratio (P = 0.034) and the presence of ESD (P = 0.018). We conducted principal component (PC) analysis on a beta-diversity matrix (pairwise difference in microbiota), and observed significant correlations between PC1, PC3, and PGI/II (P = 0.004 and 0.009, respectively), and between PC1 and ESD (P = 0.003). CONCLUSIONS: Lower microbial richness in upper digestive tract was independently associated with both cancer-predisposing states in the esophagus and stomach (presence of ESD and lower PGI/II). IMPACT: These novel findings suggest that the upper digestive tract microbiota may play a role in the etiology of chronic atrophic gastritis and ESD, and therefore in the development of gastric and esophageal cancers.

In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 x 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 x 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases.

Vitamin D has been hypothesized to protect against cancer. We followed 16,819 participants in NHANES III (Third National Health and Nutritional Examination Survey) from 1988 to 2006, expanding on an earlier NHANES III study (1988-2000). Using Cox proportional hazards regression models, we examined risk related to baseline serum 25-hydroxyvitamin D [25(OH)D] for total cancer mortality, in both sexes, and by racial/ethnic groups, as well as for site-specific cancers. Because serum was collected in the south in cooler months and in the north in warmer months, we examined associations by collection season ("summer/higher latitude" and "winter/lower latitude"). We identified 884 cancer deaths during 225,212 person-years. Overall cancer mortality risks were unrelated to baseline 25(OH)D status in both season/latitude groups, and in non-Hispanic whites, non-Hispanic blacks, and Mexican-Americans. In men, risks were elevated at higher levels {e.g., for ≥100 nmol/L, relative risk (RR) = 1.85 [95% confidence interval (CI), 1.02-3.35] compared with <37.5 nmol/L}. Although risks were unrelated to 25(OH)D in all women combined, risks significantly decreased with increasing 25(OH)D in the summer/higher latitude group [for ≥100 nmol/L, RR = 0.52 (95% CI, 0.25-1.15) compared with <37.5 nmol/L; P(trend) = 0.03, based on continuous values]. We also observed a suggestion of an inverse association with colorectal cancer mortality (P(trend) = 0.09) and a positive association with lung cancer mortality among males (P(trend) = 0.03). Our results do not support the hypothesis that 25(OH)D is associated with reduced cancer mortality. Although cancer mortality in females was inversely associated with 25(OH)D in the summer/higher latitude group, cancer mortality at some sites was increased among men with higher 25(OH)D. These findings argue for caution before increasing 25(OH)D levels to prevent cancer.