Search tips
Search criteria

Results 1-25 (65)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
Document Types
1.  Genetic variants in Fas signaling pathway genes and risk of gastric cancer 
Populations in north central China are at high risk for gastric cancers (GC), and altered FAS-mediated cell signaling and/or apoptosis may contribute to this risk. We examined the association of 554 single nucleotide polymorphisms (SNPs) in 53 Fas signaling-related genes using a pathway-based approach in 1758 GC cases (1126 gastric cardia adenocarcinomas (GCA) and 632 gastric noncardia adenocarcinomas (GNCA)), and 2111 controls from a genome-wide association study (GWAS) of GC in ethnic Chinese. SNP associations with risk of overall GC, GCA and GNCA were evaluated using unconditional logistic regressions controlling for age, sex and study. Gene- and pathway-based associations were tested using the adaptive rank-truncated product (ARTP) method. Statistical significance was evaluated empirically by permutation. Significant pathway-based associations were observed for Fas signaling with risk of overall GC (P = 5.5E-04) and GCA (P = 6.3E-03), but not GNCA (P = 8.1E-02). Among examined genes in the Fas signaling pathway, MAP2K4, FAF1, MAPK8, CASP10, CASP8, CFLAR, MAP2K1, CAP8AP2, PAK2 and IKBKB were associated with risk of GC (nominal P < 0.05), and FAF1 and MAPK8 were significantly associated with risk of both GCA and GNCA (nominal P < 0.05). Our examination of genetic variation in the Fas signaling pathway is consistent with an association of altered Fas signaling and/or apoptosis with risk of GC. As one of the first attempts to investigate a pathway-level association, our results suggest that these genes and the Fas signaling pathway warrant further evaluation in relation to GC risk in other populations.
PMCID: PMC3858487  PMID: 23921907
Gastric cancer; gastric cardia; gastric noncardia; Fas signaling; genetic variants; GWAS; single nucleotide polymorphisms; pathway genes
2.  The association between the upper digestive tract microbiota by HOMIM and oral health in a population-based study in Linxian, China 
BMC Public Health  2014;14(1):1110.
Bacteria affect oral health, but few studies have systematically examined the role of bacterial communities in oral diseases. We examined this relationship in a large population-based Chinese cancer screening cohort.
Human Oral Microbe Identification Microarrays were used to test for the presence of 272 human oral bacterial species (97 genera) in upper digestive tract (UDT) samples collected from 659 participants. Oral health was assessed using US NHANES (National Health and Nutrition Examination Survey) protocols. We assessed both dental health (total teeth missing; tooth decay; and the decayed, missing, and filled teeth (DMFT) score) and periodontal health (bleeding on probing (BoP) extent score, loss of attachment extent score, and a periodontitis summary estimate).
Microbial richness, estimated by number of genera per sample, was positively correlated with BoP score (P = 0.015), but negatively correlated with tooth decay and DMFT score (P = 0.008 and 0.022 respectively). Regarding β-diversity, as estimated by the UniFrac distance matrix for pairwise differences among samples, at least one of the first three principal components of the UniFrac distance matrix was correlated with the number of missing teeth, tooth decay, DMFT, BoP, or periodontitis. Of the examined genera, Parvimonas was positively associated with BoP and periodontitis. Veillonellacease [G-1] was associated with a high DMFT score, and Filifactor and Peptostreptococcus were associated with a low DMFT score.
Our results suggest distinct relationships between UDT microbiota and dental and periodontal health. Poor dental health was associated with a less microbial diversity, whereas poor periodontal health was associated with more diversity and the presence of potentially pathogenic species.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2458-14-1110) contains supplementary material, which is available to authorized users.
PMCID: PMC4223728  PMID: 25348940
Microbiota; Oral health; Dental caries; Periodontitis; Bleeding on probe; Attachment loss
3.  Index-Based Dietary Patterns and Risk of Esophageal and Gastric Cancer in a Large Cohort Study 
Background & Aims
Diet could affect risk for esophageal and gastric cancers, but associations have been inconsistent. The diet is complex, so studies of dietary patterns, rather than studies of individual foods, might be more likely to identify cancer risk factors. There is limited research on index-based dietary patterns and esophageal and gastric cancers. We prospectively evaluated associations between the Healthy Eating Index-2005 (HEI-2005) and alternate Mediterranean Diet (aMED) scores and risk of esophageal and gastric cancers.
We analyzed data from 494,968 participants in the National Institutes of Health (NIH)-AARP Diet and Health study, in which AARP members (51–70 y old) completed a self-administered baseline food frequency questionnaire between 1995 and 1996. Their answers were used to estimate scores for each index.
During the follow-up period (1995–2006), participants developed 215 esophageal squamous cell carcinomas (ESCCs), 633 esophageal adenocarcinomas (EACs), 453 gastric cardia adenocarcinomas, and 501 gastric non-cardia adenocarcinomas. Higher scores from the HEI-2005 were associated with a reduced risk of ESCC (comparing the highest quintile with the lowest: hazard ratio [HR], 0.51; 95% confidence interval [CI], 0.31–0.86; Ptrend=.001) and EAC (HR, 0.75; 95% CI, 0.57–0.98; Ptrend=.01). We observed an inverse association between ESCC, but not EAC, and higher aMED score (meaning a higher-quality diet). HEI-2005 and aMED scores were not significantly associated with gastric cardia or noncardia adenocarcinomas.
Using data collected from 1995 through 2006 from the NIH-AARP Diet and Health Study, HEI-2005 and aMED scores were inversely associated with risk for esophageal cancers—particularly ESCC. Adherence to dietary recommendations might help prevent esophageal cancers.
PMCID: PMC3758458  PMID: 23591281
food habits; esophageal neoplasms; stomach neoplasms
4.  Gastroesophageal Reflux in Relation to Adenocarcinomas of the Esophagus: A Pooled Analysis from the Barrett’s and Esophageal Adenocarcinoma Consortium (BEACON) 
PLoS ONE  2014;9(7):e103508.
Previous studies have evidenced an association between gastroesophageal reflux and esophageal adenocarcinoma (EA). It is unknown to what extent these associations vary by population, age, sex, body mass index, and cigarette smoking, or whether duration and frequency of symptoms interact in predicting risk. The Barrett’s and Esophageal Adenocarcinoma Consortium (BEACON) allowed an in-depth assessment of these issues.
Detailed information on heartburn and regurgitation symptoms and covariates were available from five BEACON case-control studies of EA and esophagogastric junction adenocarcinoma (EGJA). We conducted single-study multivariable logistic regressions followed by random-effects meta-analysis. Stratified analyses, meta-regressions, and sensitivity analyses were also conducted.
Five studies provided 1,128 EA cases, 1,229 EGJA cases, and 4,057 controls for analysis. All summary estimates indicated positive, significant associations between heartburn/regurgitation symptoms and EA. Increasing heartburn duration was associated with increasing EA risk; odds ratios were 2.80, 3.85, and 6.24 for symptom durations of <10 years, 10 to <20 years, and ≥20 years. Associations with EGJA were slighter weaker, but still statistically significant for those with the highest exposure. Both frequency and duration of heartburn/regurgitation symptoms were independently associated with higher risk. We observed similar strengths of associations when stratified by age, sex, cigarette smoking, and body mass index.
This analysis indicates that the association between heartburn/regurgitation symptoms and EA is strong, increases with increased duration and/or frequency, and is consistent across major risk factors. Weaker associations for EGJA suggest that this cancer site has a dissimilar pathogenesis or represents a mixed population of patients.
PMCID: PMC4116205  PMID: 25075959
5.  Genetic variants in DNA repair pathway genes and risk of esophageal squamous cell carcinoma and gastric adenocarcinoma in a Chinese population 
Carcinogenesis  2013;34(7):1536-1542.
The DNA repair pathways help to maintain genomic integrity and therefore genetic variation in the pathways could affect the propensity to develop cancer. Selected germline single nucleotide polymorphisms (SNPs) in the pathways have been associated with esophageal cancer and gastric cancer (GC) but few studies have comprehensively examined the pathway genes. We aimed to investigate associations between DNA repair pathway genes and risk of esophageal squamous cell carcinoma (ESCC) and GC, using data from a genome-wide association study in a Han Chinese population where ESCC and GC are the predominant cancers. In sum, 1942 ESCC cases, 1758 GC cases and 2111 controls from the Shanxi Upper Gastrointestinal Cancer Genetics Project (discovery set) and the Linxian Nutrition Intervention Trials (replication set) were genotyped for 1675 SNPs in 170 DNA repair-related genes. Logistic regression models were applied to evaluate SNP-level associations. Gene- and pathway-level associations were determined using the resampling-based adaptive rank-truncated product approach. The DNA repair pathways overall were significantly associated with risk of ESCC (P = 6.37 × 10− 4), but not with GC (P = 0.20). The most significant gene in ESCC was CHEK2 (P = 2.00 × 10− 6) and in GC was CLK2 (P = 3.02 × 10− 4). We observed several other genes significantly associated with either ESCC (SMUG1, TDG, TP53, GTF2H3, FEN1, POLQ, HEL308, RAD54B, MPG, FANCE and BRCA1) or GC risk (MRE11A, RAD54L and POLE) (P < 0.05). We provide evidence for an association between specific genes in the DNA repair pathways and the risk of ESCC and GC. Further studies are warranted to validate these associations and to investigate underlying mechanisms.
PMCID: PMC3697889  PMID: 23504502
6.  Soluble receptor for advanced glycation end products and risk of liver cancer 
Hepatology (Baltimore, Md.)  2013;57(6):2338-2345.
Binding of advanced glycation end products (AGEs) to their receptor (RAGE) increases oxidative stress and inflammation, and may be involved in liver injury and subsequent carcinogenesis. Soluble RAGE (sRAGE) may neutralize the effects mediated by AGEs/RAGE complex. Epidemiologic studies examining sRAGE or AGEs in association with liver cancer are lacking. We examined the associations between prediagnostic serum concentrations of sRAGE or Nε-(carboxymethyl)-lysine (CML)-AGE and hepatocellular carcinoma (HCC) in a case-cohort study within a cohort of 29,133 Finnish male smokers who completed questionnaires and provided a fasting blood sample in 1985–1988. During follow-up beginning 5 years after enrollment through April 2006, 145 liver cancers occurred. Serum concentrations of sRAGE, CML-AGE, glucose, and insulin were measured in cases and 485 randomly sampled cohort participants. Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) were available on most cases and a subset of the study population. Weighted Cox proportional hazards regression was used to calculate relative risks (RR) and 95% confidence intervals (CI), adjusted for age, years of smoking, and body mass index. sRAGE and CML-AGE concentrations were inversely associated with liver cancer (sRAGE: RR, highest versus lowest tertile, 0.77; 95% CI, 0.48–1.24; Ptrend=0.28; continuous RR, 0.86; 95% CI, 0.75–0.99; CML-AGE: RR, highest versus lowest tertile, 0.19; 95% CI, 0.10–0.35; Ptrend <0.0001; continuous RR, 0.74; 95% CI, 0.65–0.84). Further adjustment for glucose and insulin, or exclusion of cases with chronic HBV or HCV, did not change the associations.
Our results support the hypothesis that sRAGE is inversely associated with liver cancer. The findings need confirmation, particularly in populations that include women and non-smokers.
PMCID: PMC3644530  PMID: 23325627
sRAGE; CML-AGE; case-cohort; incidence; men
7.  Association of Meat and Fat Intake With Liver Disease and Hepatocellular Carcinoma in the NIH-AARP Cohort 
Several plausible mechanisms, including fat, iron, heterocyclic amines, and N-nitroso compounds, link meat intake with chronic liver disease (CLD) and hepatocellular carcinoma (HCC). Few studies have investigated these associations.
We prospectively examined the relationship between meat and associated exposures with CLD mortality (n = 551; not including HCC) and HCC incidence (n = 338) in 495 006 men and women of the National Institutes of Health–AARP Diet and Health Study. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the fifth (Q5) vs the first (Q1) quintile were estimated from multivariable adjusted Cox proportional hazards regression models. All tests of statistical significance were two-sided.
We found inverse associations between white meat and risk of CLD (HR = 0.52, 95% CI = 0.39 to 0.70, 7.5 vs 18.2 cases per 100 000 person-years) and HCC (HR = 0.52, 95% CI = 0.36 to 0.77, 5.8 vs 14.3 cases per 100 000 person-years). Red meat was associated with higher risk of CLD (HR = 2.59, 95% CI = 1.86 to 3.61, 22.3 vs 6.2 cases per 100 000 person-years) and HCC (HR = 1.74, 95% CI = 1.16 to 2.61, 14.9 vs 5.7 cases per 100 000 person-years). Among fat types, results were strongest for saturated fat (for CLD, HR = 3.50, 95% CI = 2.48 to 4.96, 23.0 vs 6.5 cases per 100 000 person-years; for HCC, HR = 1.87, 95% CI = 1.23 to 2.85, 14.5 vs 6.3 cases per 100 000 person-years). After mutual adjustment, risk estimates persisted for saturated fat, red meat, and white meat. Heme iron, processed meat, nitrate, and nitrite were positively associated with CLD but not with HCC. Individual heterocyclic amines, 2-amino-3,4,8-trimethylimidazo[4,5,-f]quinoxaline (DiMeIQx), 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), and 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP), were not associated with either outcome.
Our results suggest that red meat and saturated fat may be associated with increased CLD and HCC risk, whereas white meat may be associated with reduced risk.
PMCID: PMC2935477  PMID: 20729477
8.  Genetic variants in sex hormone metabolic pathway genes and risk of esophageal squamous cell carcinoma 
Carcinogenesis  2013;34(5):1062-1068.
In China, esophageal cancer is the fourth leading cause of cancer death where essentially all cases are histologically esophageal squamous cell carcinoma (ESCC), in contrast to esophageal adenocarcinoma in the West. Globally, ESCC is 2.4 times more common among men than women and recently it has been suggested that sex hormones may be associated with the risk of ESCC. We examined the association between genetic variants in sex hormone metabolic genes and ESCC risk in a population from north central China with high-incidence rates. A total of 1026 ESCC cases and 1452 controls were genotyped for 797 unique tag single-nucleotide polymorphisms (SNPs) in 51 sex hormone metabolic genes. SNP-, gene- and pathway-based associations with ESCC risk were evaluated using unconditional logistic regression adjusted for age, sex and geographical location and the adaptive rank truncated product (ARTP) method. Statistical significance was determined through use of permutation for pathway- and gene-based associations. No associations were observed for the overall sex hormone metabolic pathway (P = 0.14) or subpathways (androgen synthesis: P = 0.30, estrogen synthesis: P = 0.15 and estrogen removal: P = 0.19) with risk of ESCC. However, six individual genes (including SULT2B1, CYP1B1, CYP3A7, CYP3A5, SHBG and CYP11A1) were significantly associated with ESCC risk (P < 0.05). Our examination of genetic variation in the sex hormone metabolic pathway is consistent with a potential association with risk of ESCC. These positive findings warrant further evaluation in relation to ESCC risk and replication in other populations.
PMCID: PMC3643422  PMID: 23358850
9.  Sweetened Beverages, Coffee, and Tea and Depression Risk among Older US Adults 
PLoS ONE  2014;9(4):e94715.
Sweetened beverages, coffee, and tea are the most consumed non-alcoholic beverages and may have important health consequences. We prospectively evaluated the consumption of various types of beverages assessed in 1995–1996 in relation to self-reported depression diagnosis after 2000 among 263,923 participants of the NIH-AARP Diet and Health Study. Odds ratios (OR) and 95% confidence intervals (CI) were derived from multivariate logistic regressions. The OR (95% CI) comparing ≥4 cans/cups per day with none were 1.30 (95%CI: 1.17–1.44) for soft drinks, 1.38 (1.15–1.65) for fruit drinks, and 0.91 (0.84–0.98) for coffee (all P for trend<0.0001). Null associations were observed for iced-tea and hot tea. In stratified analyses by drinkers of primarily diet versus regular beverages, the ORs were 1.31 (1.16–1.47) for diet versus 1.22 (1.03–1.45) for regular soft drinks, 1.51 (1.18–1.92) for diet versus 1.08 (0.79–1.46) for regular fruit drinks, and 1.25 (1.10–1.41) for diet versus 0.94 (0.83–1.08) for regular sweetened iced-tea. Finally, compared to nondrinkers, drinking coffee or tea without any sweetener was associated with a lower risk for depression, adding artificial sweeteners, but not sugar or honey, was associated with higher risks. Frequent consumption of sweetened beverages, especially diet drinks, may increase depression risk among older adults, whereas coffee consumption may lower the risk.
PMCID: PMC3990543  PMID: 24743309
10.  Menstrual and reproductive factors and gastric cancer risk in a large prospective study of women 
Gut  2007;56(12):1671-1677.
Gastric cancer incidence rates are consistently lower in women than men in both high and low‐risk regions worldwide. Sex hormones, such as progesterone and estrogen, may protect women against gastric cancer.
To investigate the association of menstrual and reproductive factors and gastric cancer risk.
These associations were prospectively investigated in 73 442 Shanghai women. After 419 260 person‐years of follow‐up, 154 women were diagnosed with gastric cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models adjusted for age, body mass index, education, income, and cigarette use.
No associations were observed between gastric cancer risk and age of menarche, number of children, breast feeding, or oral contraceptive use. In contrast, associations were observed with age of menopause (HR 0.80 per five‐year increase in menopausal age, 95% CI 0.66–0.97), years of fertility (participants with less than 30 years of fertility were at increased risk compared with those with 30–36 years of fertility, HR 1.90, 95% CI 1.25–2.90), years since menopause (HR 1.26 per five years, 95% CI 1.03–1.53), and intrauterine device use (HR for users 1.61, 95% CI 1.08–2.39).
These results support the hypothesis that female hormones play a protective role in gastric cancer risk.
PMCID: PMC2095686  PMID: 17627962
stomach neoplasms; cohort studies; prospective studies; hormones
11.  Alcohol consumption, folate intake, hepatocellular carcinoma and liver disease mortality 
Excessive alcohol consumption is a well-established risk factor for liver disease and hepatocellular carcinoma (HCC). Previous studies have found that increased alcohol consumption can lead to lower absorption of folate. Conversely, higher folate intake has been inversely associated with liver damage and HCC. In the current study, we investigate the effect of alcohol consumption and folate intake on HCC incidence and liver disease mortality in the NIH-AARP Diet and Health Study.
The study population included 494,743 participants who reported at baseline their dietary intake for the previous year. Alcohol and folate were analyzed with hazard ratios (HR) and 95% confidence intervals (CI) using multivariate Cox proportional hazards regression models adjusted for age, sex, race, education, smoking, body mass index and diabetes. HCC incidence (n=435) was determined through 2006 via linkage with cancer registries and liver disease mortality (n=789) was determined through 2008 via linkage to the National Death Index Plus.
Consumption of more than three drinks per day was positively associated with both HCC incidence (HR: 1.92; 95%CI: 1.42–2.60) and liver disease mortality (HR: 5.84; 95%CI: 4.81–7.10), while folate intake was associated with neither outcome. Folate, however, modified the relationship between alcohol and HCC incidence (Pinteraction=0.03), but had no effect on the relationship between alcohol and liver disease mortality (Pinteraction=0.54).
These results suggest that higher folate intake may ameliorate the effect of alcohol consumption on the development of HCC.
Folate intake may be beneficial in the prevention of alcohol-associated HCC.
PMCID: PMC3596467  PMID: 23307533
Folate; Alcohol; hepatocellular carcinoma; liver disease; epidemiology
12.  Smoking water-pipe, chewing nass, and prevalence of heart disease – A cross-sectional analysis of baseline data from the Golestan Cohort Study, Iran 
Heart (British Cardiac Society)  2012;99(4):272-278.
Water-pipe and smokeless tobacco use have been associated with several adverse health outcomes. However, little information is available on the association between water-pipe use and heart disease (HD). Therefore, we investigated the association of smoking water-pipe and chewing nass (a mixture of tobacco, lime, and ash) with prevalent HD.
Cross-sectional study.
Baseline data (collected in 2004–2008) from a prospective population-based study in Golestan Province, Iran.
50,045 residents of Golestan (40–75 years old; 42.4% male).
Main outcome measures
ORs and 95% CIs from multivariate logistic regression models for the association of water-pipe and nass use with HD prevalence.
A total of 3051 (6.1%) participants reported a history of HD, and 525 (1.1%) and 3726 (7.5%) reported ever water-pipe or nass use, respectively. Heavy water-pipe smoking was significantly associated with HD prevalence (highest level of cumulative use versus never use, OR= 3.75; 95% CI 1.52 – 9.22; P for trend= 0.04). This association persisted when using different cutoff points, when restricting HD to those taking nitrate compound medications, and among never cigarette smokers. There was no significant association between nass use and HD prevalence (highest category of use versus never use, OR= 0.91; 95% CI 0.69 – 1.20).
Our study suggests a significant association between HD and heavy water-pipe smoking. Although the existing evidence suggesting similar biological consequences of water-pipe and cigarette smoking make this association plausible, results of our study were based on a modest number of water-pipe users and need to be replicated in further studies.
PMCID: PMC3671096  PMID: 23257174
hookah; ischemic heart disease; nass; tobacco; water-pipe
13.  Alcohol and acetaldehyde in African fermented milk mursik – A possible etiological factor for high incidence of esophageal cancer in western Kenya 
Esophageal cancer is unusually frequent in western Kenya, despite the low prevalence of classical risk factors such as heavy drinking and tobacco smoking. Among Kenyans consumption of fermented milk is an old tradition. Our hypothesis is that alcohol and acetaldehyde are produced during the fermentation process and that their carcinogenic potential contributes to the high incidence of esophageal cancer.
Eight samples of mursik milk starter cultures were collected from different Kalenjin families in the Rift Valley province, Western Kenya. A protocol provided by the families was used for milk fermentation. Ethanol and acetaldehyde levels were measured by gas chromatography. The microbial flora in starter cultures was identified by 16S and 18S sequencing.
7/8 starter cultures produced mutagenic (>100 µM) levels of acetaldehyde and 4/8 starter cultures produced >1000 µM of acetaldehyde. The highest alcohol levels (mean 79.4 mM) were detected in the four fermented milks with highest acetaldehyde production. The mean number of microbial species in the starter cultures was 5 (range 2–8). Yeasts were identified in all starter cultures (mean 1.5 species/milk) but their proportion of the total microbial count varied markedly (mean 35%, range 7–90%). A combination of yeast and lactobacilli, especially Candida krusei with Lactobacillus kefiriwith the exclusion of other species, seemed to correlate with higher acetaldehyde and ethanol levels.
Significant levels of ethanol and acetaldehyde were produced during mursik fermentation.
When ingested several times daily the repeated exposure to carcinogenic levels of acetaldehyde may contribute to esophageal carcinogenesis.
PMCID: PMC3538938  PMID: 23155139
Candida; carcinogenesis; ethanol; fermented milk; lactobacilli
14.  Physical Activity and Sedentary Behavior in Relation to Esophageal and Gastric Cancers in the NIH-AARP Cohort 
PLoS ONE  2013;8(12):e84805.
Body mass index is known to be positively associated with an increased risk of adenocarcinomas of the esophagus, yet there is there limited evidence on whether physical activity or sedentary behavior affects risk of histology- and site-specific upper gastrointestinal cancers. We used the NIH-AARP Diet and Health Study to assess these exposures in relation to esophageal adenocarcinoma (EA), esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and gastric non-cardia adenocarcinoma (GNCA).
Self-administered questionnaires were used to elicit physical activity and sedentary behavior exposures at various age periods. Cohort members were followed via linkage to the US Postal Service National Change of Address database, the Social Security Administration Death Master File, and the National Death Index. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95 percent confidence intervals (95%CI)
During 4.8 million person years, there were a total of 215 incident ESCCs, 631 EAs, 453 GCAs, and 501 GNCAs for analysis. Strenuous physical activity in the last 12 months (HR>5 times/week vs. never=0.58, 95%CI: 0.39, 0.88) and typical physical activity and sports during ages 15–18 years (p for trend=0.01) were each inversely associated with GNCA risk. Increased sedentary behavior was inversely associated with EA (HR5–6 hrs/day vs. <1 hr=0.57, 95%CI: 0.36, 0.92). There was no evidence that BMI was a confounder or effect modifier of any relationship. After adjustment for multiple testing, none of these results were deemed to be statistically significant at p<0.05.
We find evidence for an inverse association between physical activity and GNCA risk. Associations between body mass index and adenocarcinomas of the esophagus do not appear to be related to physical activity and sedentary behavior.
PMCID: PMC3868613  PMID: 24367697
15.  Nonsteroidal Anti-inflammatory Drug Use, Chronic Liver Disease, and Hepatocellular Carcinoma 
Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce chronic inflammation and risk of many cancers, but their effect on risk of hepatocellular carcinoma (HCC) and death due to chronic liver disease (CLD) has not been investigated.
We analyzed prospective data on 300504 men and women aged 50 to 71 years in the National Institutes of Health–AARP Diet and Health Study cohort and linked self-reported aspirin and nonaspirin NSAID use with registry-confirmed diagnoses of HCC (n=250) and death due to CLD (n=428, excluding HCC). We calculated hazard rate ratios (RRs) and their two-sided 95% confidence intervals (CIs) using Cox proportional hazard regression models with adjustment for age, sex, race/ethnicity, cigarette smoking, alcohol consumption, diabetes, and body mass index. All tests of statistical significance were two-sided.
Aspirin users had statistically significant reduced risks of incidence of HCC (RR = 0.59; 95% CI = 0.45 to 0.77) and mortality due to CLD (RR = 0.55; 95% CI = 0.45 to 0.67) compared to those who did not use aspirin. In contrast, users of nonaspirin NSAIDs had a reduced risk of mortality due to CLD (RR = 0.74; 95% CI= 0.61 to 0.90) but did not have lower risk of incidence of HCC (RR = 1.08; 95% CI = 0.84 to 1.39) compared to those who did not use nonaspirin NSAIDs. The risk estimates did not vary in statistical significance by frequency (monthly, weekly, daily) of aspirin use, but the reduced risk of mortality due to CLD was statistically significant only among monthly users of nonaspirin NSAIDs compared to non-users.
Aspirin use was associated with reduced risk of developing HCC and of death due to CLD whereas nonaspirin NSAID use was only associated with reduced risk of death due to CLD.
PMCID: PMC3514167  PMID: 23197492
16.  Measuring telomere length for the early detection of precursor lesions of esophageal squamous cell carcinoma 
BMC Cancer  2013;13:578.
Esophageal cancer is the sixth leading cause of cancer death worldwide; current early detection screening tests are inadequate. Esophageal balloon cytology successfully retrieves exfoliated and scraped superficial esophageal epithelial cells, but cytologic reading of these cells has poor sensitivity and specificity for detecting esophageal squamous dysplasia (ESD), the precursor lesion of esophageal squamous cell carcinoma (ESCC). Measuring telomere length, a marker for chromosomal instability, may improve the utility of balloon cytology for detecting ESD and early ESCC.
We examined balloon cytology specimens from 89 asymptomatic cases of ESD (37 low-grade and 52 high-grade) and 92 age- and sex-matched normal controls from an esophageal cancer early detection screening study. All subjects also underwent endoscopy and biopsy, and ESD was diagnosed histopathologically. DNA was extracted from the balloon cytology cells, and telomere length was measured by quantitative PCR. A receiver operating characteristic (ROC) curve was plotted for telomere length as a diagnostic marker for high-grade dysplasia.
Telomere lengths were comparable among the low- and high-grade dysplasia cases and controls, with means of 0.96, 0.96, and 0.92, respectively. The area under the ROC curve was 0.55 for telomere length as a diagnostic marker for high-grade dysplasia. Further adjustment for subject characteristics, including sex, age, smoking, drinking, hypertension, and body mass index did not improve the use of telomere length as a marker for ESD.
Telomere length of esophageal balloon cytology cells was not associated with ESCC precursor lesions. Therefore, telomere length shows little promise as an early detection marker for ESCC in esophageal balloon samples.
PMCID: PMC3882883  PMID: 24308314
Esophageal squamous cell carcinoma; Esophageal squamous dysplasia; Early detection; Screening; Balloon cytology; Telomeres
17.  Common obesity-related genetic variants and papillary thyroid cancer risk 
Epidemiologic studies have shown consistent associations between obesity and increased thyroid cancer risk, but, to date, no studies have investigated the relationship between thyroid cancer risk and obesity-related single nucleotide polymorphisms (SNPs).
We evaluated 575 tag SNPs in 23 obesity-related gene regions in a case-control study of 341 incident papillary thyroid cancer (PTC) cases and 444 controls of European ancestry. Logistic regression models, adjusted for attained age, year of birth, and sex were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) with SNP genotypes, coded as 0, 1, and 2 and modeled continuously to calculate P-trends.
Nine out of 10 top-ranking SNPs (Ptrend<0.01) were located in the FTO (fat mass and obesity associated) gene region, while the other was located in INSR (insulin receptor). None of the associations were significant after correcting for multiple testing.
Our data do not support an important role of obesity-related genetic polymorphisms in determining the risk of PTC.
Factors other than selected genetic polymorphisms may be responsible for the observed associations between obesity and increased PTC risk.
PMCID: PMC3518668  PMID: 23064004
single nucleotide polymorphisms; case-control study; obesity; body mass index; thyroid neoplasms
18.  Alcohol Consumption, One-Carbon Metabolites, Liver Cancer and Liver Disease Mortality 
PLoS ONE  2013;8(10):e78156.
Excess alcohol consumption adversely affects one-carbon metabolism and increases the risk of liver disease and liver cancer. Conversely, higher folate levels have been inversely associated with liver damage. The current study investigated the effects of alcohol and one-carbon metabolite intake on liver cancer incidence and liver disease mortality within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study.
Cox proportional hazards modeling was used to calculate hazard ratios and 95% confidence intervals (CIs) in a population of 27,086 Finnish males with 194 incident liver cancers and 213 liver disease deaths. In a nested case-control subset (95 liver cancers, 103 controls), logistic regression was used to calculate odds ratios and 95% CIs for serum one-carbon metabolites in relation to liver cancer risk.
Daily alcohol consumption of more than 20.44 g was associated with an increased risk of both liver cancer incidence (Hazard Ratio (HR) 1.52, 95%CI 1.06–2.18) and liver disease mortality (HR 6.68, 95%CI 4.16–10.71). These risks were unaffected by one-carbon metabolite intake. Similarly, in the case-control study, none of the serum one-carbon metabolites were associated with liver cancer.
The current study provided no convincing evidence for a protective association of one-carbon metabolite intake or serum level on the risk of liver cancer or liver disease mortality.
PMCID: PMC3810254  PMID: 24205137
19.  Genome-wide association studies of gastric adenocarcinoma and esophageal squamous cell carcinoma identify a shared susceptibility locus in PLCE1 at 10q23 
Nature genetics  2012;44(10):1090-1097.
We conducted a genome-wide association study of gastric cancer (GC) and esophageal squamous cell carcinoma (ESCC) in ethnic Chinese subjects in which we genotyped 551,152 single nucleotide polymorphisms (SNPs). We report a combined analysis of 2,240 GC cases, 2,115 ESCC cases, and 3,302 controls drawn from five studies. In logistic regression models adjusted for age, sex, and study, multiple variants at 10q23 had genome-wide significance for GC and ESCC independently. A notable signal was rs2274223, a nonsynonymous SNP located in PLCE1, for GC (P=8.40×1010; per allele odds ratio (OR) = 1.31) and ESCC (P=3.85×10−9; OR = 1.34). The association with GC differed by anatomic subsite. For tumors located in the cardia the association was stronger (P=4.19 × 10−15; OR= 1.57) and for those located in the noncardia stomach it was absent (P=0.44; OR=1.05). Our findings at 10q23 could provide insight into the high incidence rates of both cancers in China.
PMCID: PMC3513832  PMID: 22960999
20.  Association of dietary fat intakes with risk of esophageal and gastric cancer in the NIH-AARP Diet and Health study 
The aim of this study was to investigate whether intakes of total fat and fat subtypes were associated with esophageal adenocarcinoma (EAC), esophageal squamous cell carcinoma (ESCC), gastric cardia or gastric non-cardia adenocarcinoma. From 1995–1996, dietary intake data was reported by 494,978 participants of the NIH-AARP cohort. 630 EAC, 215 ESCC, 454 gastric cardia and 501 gastric non-cardia adenocarcinomas accrued to the cohort. Cox proportional hazards regression was used to examine the association between the dietary fat intakes, whilst adjusting for potential confounders. Though apparent associations were observed in energy-adjusted models, multivariate adjustment attenuated results to null (e.g. EAC energy adjusted hazard ratio (HR) and 95% confidence interval (95%CI) 1.66 (1.27–2.18) P for trend <0.01; EAC multivariate adjusted HR (95%CI) 1.17 (0.84–1.64) P for trend=0.58). Similar patterns were also observed for fat subtypes (e.g. EAC saturated fat, energy adjusted HR (95%CI) 1.79 (1.37–2.33) P for trend <0.01; EAC saturated fat, multivariate adjusted HR (95%CI) 1.27 (0.91–1.78) P for trend=0.28). However, in multivariate models an inverse association for polyunsaturated fat (continuous) was seen for EAC in subjects with a body mass index (BMI) in the normal range (18.5–<25 kg/m2) (HR (95%CI) 0.76 (0.63–0.92)), that was not present in overweight subjects (HR (95%CI) 1.04 (0.96–1.14)), or in unstratified analysis (HR (95%CI) 0.97 (0.90–1.05)). P for interaction=0.02. Overall, we found null associations between the dietary fat intakes with esophageal or gastric cancer risk; though a protective effect of polyunsaturated fat intake was seen for EAC in subjects with a normal BMI.
PMCID: PMC3346853  PMID: 22116732
cohort; dietary fat; esophageal neoplasms; stomach neoplasms; prospective
21.  A Prospective Investigation of Coffee Drinking and Endometrial Cancer Incidence 
Coffee drinking may be associated with reduced risk of endometrial cancer; however, prospective data are limited. Further, it is not clear whether any association between coffee and endometrial cancer differs according to coffee caffeine content. The association of coffee drinking with incidence of endometrial cancer was evaluated among 226,732 women, aged 50–71, enrolled in the NIH-AARP Diet and Health Study who completed a baseline epidemiologic questionnaire. Following a mean 9.3 years of follow-up, data were available for 1,486 incident endometrial cancer cases. Cox proportional hazards models were used to estimate associations of coffee with endometrial cancer incidence. Sub-group analyses were performed according to smoking status, hormone therapy use (HT) and body habitus. Coffee drinking was inversely related to incidence of endometrial cancer (Hazard Ratio [HR] comparing drinking of >3 cups/day versus no cups=0.64, 95%CI, 0.51–0.80; Ptrend= 0.0004). The association of coffee with endometrial cancer risk was apparent for consumption of both regular (HR per cup= 0.90, 95%CI, 0.86–0.95) and decaffeinated coffee (HR per cup=0.93, 95%CI, 0.87–0.99). The relation of coffee with endometrial cancer incidence varied significantly by HT use (Pinteraction=0.03) with an association only apparent among HT-never users (HR comparing drinking >3 cups/day versus no cups= 0.54, 95%CI, 0.41–0.72; Ptrend=0.0005). Endometrial cancer incidence appears to be reduced among women that habitually drink coffee, an association that does not differ according to caffeine content.
PMCID: PMC3288610  PMID: 22021096
22.  Anthropometric Measures and Physical Activity and the Risk of Lung Cancer in Never-Smokers: A Prospective Cohort Study 
PLoS ONE  2013;8(8):e70672.
Worldwide, lung cancer in never-smokers is ranked the seventh most common cause of cancer death; however, the etiology of lung cancer in never-smokers is unclear. We investigated associations for body mass index (BMI) at various ages, waist circumference, hip circumference, and physical activity with lung cancer in 158,415 never-smokers of the NIH-AARP Diet and Health Study. Multivariable hazard ratios (HR) and 95% confidence intervals (CI) were estimated from Cox proportional hazards models. Over 11 years of follow-up, 532 lung cancer cases occurred. The risk estimate for obese (BMI≥30 kg/m2) participants at baseline was 1.21 (95%CI = 0.95–1.53) relative to those with a normal BMI between 18.5≤BMI<25.0. Overweight (25.0≤BMI<30.0) at age 18 (HRoverweight-vs-normal = 1.51;95%CI = 1.01–2.26) and time spent sitting (HR≥3 hrs-vs-<3 hrs = 1.32;95%CI = 1.00–1.73) was each associated with lung cancer after adjustment for baseline BMI, as was waist (HRQ4-vs-Q1 = 1.75;95%CI = 1.09–2.79) and hip circumference (HRQ4-vs-Q1 = 0.62;95%CI = 0.39–0.99), after mutual adjustment for each other and baseline BMI. No associations were observed for vigorous activity or television watching. In summary, using a large prospective cohort study, we found no evidence that BMI at baseline or middle age was associated with decreased lung cancer risk in never smokers. If anything, we observed some evidence for positive associations with a larger BMI or waist circumference.
PMCID: PMC3734257  PMID: 23940620
23.  50-Year Trends in Smoking-Related Mortality in the United States 
The New England journal of medicine  2013;368(4):351-364.
The disease risks from cigarette smoking increased in the United States over most of the 20th century, first among male smokers and later among female smokers. Whether these risks have continued to increase during the past 20 years is unclear.
We measured temporal trends in mortality across three time periods (1959–1965, 1982–1988, and 2000–2010), comparing absolute and relative risks according to sex and self-reported smoking status in two historical cohort studies and in five pooled contemporary cohort studies, among participants who became 55 years of age or older during follow-up.
For women who were current smokers, as compared with women who had never smoked, the relative risks of death from lung cancer were 2.73, 12.65, and 25.66 in the 1960s, 1980s, and contemporary cohorts, respectively; corresponding relative risks for male current smokers, as compared with men who had never smoked, were 12.22, 23.81, and 24.97. In the contemporary cohorts, male and female current smokers also had similar relative risks for death from chronic obstructive pulmonary disease (COPD) (25.61 for men and 22.35 for women), ischemic heart disease (2.50 for men and 2.86 for women), any type of stroke (1.92 for men and 2.10 for women), and all causes combined (2.80 for men and 2.76 for women). Mortality from COPD among male smokers continued to increase in the contemporary cohorts in nearly all the age groups represented in the study and within each stratum of duration and intensity of smoking. Among men 55 to 74 years of age and women 60 to 74 years of age, all-cause mortality was at least three times as high among current smokers as among those who had never smoked. Smoking cessation at any age dramatically reduced death rates.
The risk of death from cigarette smoking continues to increase among women and the increased risks are now nearly identical for men and women, as compared with persons who have never smoked. Among men, the risks associated with smoking have plateaued at the high levels seen in the 1980s, except for a continuing, unexplained increase in mortality from COPD.
PMCID: PMC3632080  PMID: 23343064
24.  Genetic Variants in Epidermal Growth Factor Receptor Pathway Genes and Risk of Esophageal Squamous Cell Carcinoma and Gastric Cancer in a Chinese Population 
PLoS ONE  2013;8(7):e68999.
The epidermal growth factor receptor (EGFR) signaling pathway regulates cell proliferation, differentiation, and survival, and is frequently dysregulated in esophageal and gastric cancers. Few studies have comprehensively examined the association between germline genetic variants in the EGFR pathway and risk of esophageal and gastric cancers. Based on a genome-wide association study in a Han Chinese population, we examined 3443 SNPs in 127 genes in the EGFR pathway for 1942 esophageal squamous cell carcinomas (ESCCs), 1758 gastric cancers (GCs), and 2111 controls. SNP-level analyses were conducted using logistic regression models. We applied the resampling-based adaptive rank truncated product approach to determine the gene- and pathway-level associations. The EGFR pathway was significantly associated with GC risk (P = 2.16×10−3). Gene-level analyses found 10 genes to be associated with GC, including FYN, MAPK8, MAP2K4, GNAI3, MAP2K1, TLN1, PRLR, PLCG2, RPS6KB2, and PIK3R3 (P<0.05). For ESCC, we did not observe a significant pathway-level association (P = 0.72), but gene-level analyses suggested associations between GNAI3, CHRNE, PAK4, WASL, and ITCH, and ESCC (P<0.05). Our data suggest an association between specific genes in the EGFR signaling pathway and risk of GC and ESCC. Further studies are warranted to validate these associations and to investigate underlying mechanisms.
PMCID: PMC3715462  PMID: 23874846
25.  Coffee intake and breast cancer risk in the NIH-AARP Diet and Health Cohort Study 
There are several biologic mechanisms whereby coffee might reduce breast cancer risk. Caffeine and caffeic acid, major coffee constituents, have been shown to suppress mammary tumor formation in animal models and to inhibit DNA methylation in human breast cancer cells, respectively. Coffee may also reduce risk through decreasing inflammation and influencing estrogen metabolism. However, epidemiologic studies have been inconsistent and few studies have examined the association by estrogen and progesterone receptor (ER/PR) status. We evaluated coffee intake for its effect on incident breast cancer in the NIH-AARP Diet and Health Study cohort, which included 198,404 women aged 50–71 with no history of cancer, who in 1995–1996 completed a questionnaire capturing usual coffee intake over the past year. State cancer registry and mortality index linkage identified 9,915 primary incident breast carcinomas through December 2006; available information on hormone receptor status identified 2,051 ER+/PR+ and 453 ER−/PR− cancers. In multivariate proportional hazards models, coffee intake was not associated with breast cancer risk (p-value for trend=0.38) (relative risk=0.98, 95% confidence interval: 0.91–1.07, for ≥ 4 cups per day as compared to women who never drank coffee), and results did not vary by body mass index or history of benign breast biopsy (p-value for interaction >0.10). We found no evidence of a relationship with either caffeinated or decaffeinated coffee. Null findings persisted for risk of both hormone receptor positive and negative breast cancers. These findings from a large prospective cohort do not support a role of coffee intake in breast carcinogenesis.
PMCID: PMC3290744  PMID: 22020403
breast neoplasms; coffee; caffeine; cohort studies; epidemiology

Results 1-25 (65)