Opium use has been associated with higher risk of cancers of the esophagus, bladder, larynx, and lung; however, no previous study has examined its association with gastric cancer. There is also little information on the associations between hookah (water pipe) smoking or the chewing of tobacco products and the risk of gastric cancer. In a case-control study in Golestan Province of Iran, we enrolled 309 cases of gastric adenocarcinoma (118 noncardia, 161 cardia, and 30 mixed-location adenocarcinomas) and 613 matched controls. Detailed information on long-term use of opium, tobacco products, and other covariates were collected using structured and validated lifestyle and food frequency questionnaires. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were obtained using conditional logistic regression models. Opium use was associated with an increased risk of gastric adenocarcinoma, with an adjusted OR (95% CI) of 3.1 (1.9 – 5.1), and this increased risk was apparent for both anatomic subsites (cardia and noncardia). There was a dose-response effect, and individuals with the highest cumulative opium use had the strongest association (OR: 4.5; 95%CI: 2.3-8.5). We did not find a statistically significant association between the use of any of the tobacco products and risk of gastric adenocarcinoma, overall or by anatomic subsite. We showed, for the first time, an association between opium use and gastric adenocarcinoma. Given that opium use is a traditional practice in many parts of the world, these results are of public health significance.
Opium; Adenocarcinoma; Cardia
Poor oral health and tooth loss have been proposed as possible risk
factors for some chronic diseases, including gastric cancer. However only a
small number of studies have tested these associations.
We conducted a case-control study in Golestan Province, Iran, that
enrolled 309 cases diagnosed with gastric adenocarcinoma (118 noncardia, 161
cardia, and 30 mixed-locations) and 613 sex, age and neighborhood matched
controls. Data on oral health were obtained through physical examination and
questionnaire including tooth loss, the number of decayed, missing, and
filled teeth, and frequency of tooth brushing. Odds ratios (ORs) and
95% confidence intervals (95% CIs) were obtained using
conditional logistic regression models adjusted for potential confounders.
Standard one degree-of-freedom linear trend test and a multiple degree of
freedom global test of the effect of adding oral hygiene variables to the
model were also calculated.
Our results showed apparent associations between tooth loss and DMFT
score with risk of gastric cancer, overall and at each anatomic subsite.
However, these associations were not monotonic and were strongly confounded
by age. The results also showed that subjects who brushed their teeth less
than daily were at significantly higher risk for gastric cardia
adenocarcinoma OR (95% CI) of 5.6 (1.6–19.3).
We found evidence for an association between oral health and gastric
cancer, but the non- monotonic association, the relatively strong effect of
confounder adjustment, and inconsistent results across studies must temper
the strength of any conclusions.
Adenocarcinoma; Tooth loss; Oral health; Stomach
This study tests the hypothesis that pre-diagnostic serum levels of twenty cancer-associated inflammatory biomarkers correlate directly with future development of head & neck, esophageal, and lung cancers in a high-risk prospective cohort.
This is a nested case-control pilot study of subjects enrolled in the Golestan Cohort Study, an ongoing epidemiologic project assessing cancer trends in Golestan, Iran. We measured a panel of 20 cytokines, chemokines, and inflammatory molecules using Luminex® technology in serum samples collected two or more years before cancer diagnosis in 78 aerodigestive cancer cases and 81 controls. Data was analyzed using Wilcoxon rank-sum test, odds ratios (OR), ROC areas of discrimination, and multivariate analysis.
Biomarkers were profoundly and globally elevated in future esophageal and lung cancer patients compared to controls. Odds ratios were significant for association between several biomarkers and future development of esophageal cancer, including IL-1Rα (35.88), IFNα2 (34), FGF-2 (17.43), GM-CSF (17.43), et al. The same trend was observed among future lung cancer cases for G-CSF (27.68), GM-CSF (13.33), TNF-α (8.55), et al. By contrast, the majority of biomarkers studied showed no significant correlation with future head and neck cancer development.
This study provides the first direct evidence that multiple inflammatory biomarkers are coordinately elevated in future lung and esophageal cancer patients two or more years before cancer diagnosis.
Serum Inflammatory Biomarker; Esophageal Squamous Cell Carcinoma; Head and Neck Squamous Cell Carcinoma; Lung Cancer; Aerodigestive Cancer
Germline genetic variants in PLCE1 (10q23) have demonstrated consistent associations with risk of esophageal squamous cell carcinoma (ESCC) and gastric cancer among Chinese. We evaluated PLCE1 mRNA and protein expression in paired tumor-normal tissues, and their relationship with survival.
PLCE1 mRNA was profiled using three probes in the Affymetrix GeneChip U133 for paired tumor-normal tissues of ESCC (n=132), gastric cardia adenocarcinoma (GCA, n=62) and gastric noncardia adenocarcinoma (GNCA, n=72). We used immunohistochemistry to detect PLCE1 protein on slides from tissue microarrays in paired tumor-normal tissues of ESCC (n=303), and tumors of GCA (n=298) and GNCA (n=124).
Compared with normal tissues, PLCE1 mRNA expression was significantly reduced in ESCC tumors (P=0.03, probe_205112_at), as well as in GCA and GNCA tumors (P<0.0001, each probe). Protein expression was non-significantly reduced in ESCC tumors (P=0.51). Increased tumor-normal mRNA fold change (probe_205112_at) was associated with longer survival in ESCC (9.6 months for highest vs lowest quartile; P-trend=0.02). Increased mRNA tumor-normal fold change (probe_205111_at) was associated with longer survival for GCA (10.7 months for highest quartile; P-trend=0.04), but not for GNCA cases (P=0.72). Similar to mRNA, elevated tumor-normal fold change for protein in ESCC was also associated with improved survival (8.1 months for highest quartile; P-trend=0.04).
Dysregulated PLCE1 mRNA expression was observed for both ESCC (one probe only) and GCA tumors, and the altered PLCE1 expression appears to be associated with cancer prognosis.
A potential role for PLCE1 in the early detection and/or therapy of ESCC and GCA warrants further investigation.
Although excess body weight has been associated with cancers of the gastric cardia, relationships with gastric cancer at other anatomic subsites are not well defined. Furthermore, subsite-specific associations with attained height have not been fully assessed.
In 1995–1996, 483,700 Whites enrolling in the multi-state NIH-AARP Diet and Health Study self-reported height and weight. Gastric cancers occurring through December 31, 2006 were ascertained from regional population-based registries. We used Cox regression models to estimate cancer hazard ratios (HRs) for sex-specific tertiles of height and weight and for body mass index (BMI) categories of the World Health Organization.
One thousand incident cancers (48% localized to the cardia, 4% fundus, 6% corpus, 3% greater curvature, 6% lesser curvature, 10% antrum, 2% pylorus, 5% overlapping lesion, and 16% unspecified) occurred an average of 5.4 years after enrollment. After controlling for effects of age, sex, education and smoking, we found an inverse association between height and total noncardia cancers (i.e., fundus, corpus, greater and lesser curvatures, antrum, and pylorus), with HRs vs. tertile 1 of 0.65 and 0.71 for tertiles 2 and 3, respectively (p-trend=0.016). Trends were consistent for individual noncardia subsites. In contrast, although weight and BMI were each associated with risk of cardia cancer, neither was associated with total noncardia cancer nor individual subsites.
Noncardia gastric cancer is associated with short stature but not with high body weight nor obesity. The excess risk for shorter adults would be consistent with the known association of chronic H. pylori infection with growth retardation during childhood.
BMI; cardia; gastric cancer; height; noncardia; weight
Esophageal cancer is one of the world’s top ten cancers. Its incidence, especially in the form of squamous cell carcinoma, is very high in some Asian regions including Kashmir. Jammu Kashmir and Ladakh are three provinces of Jammu and Kashmir, the northern most state of India. The three regions represent ethnically diverse socio-cultural populations with different incidences of esophageal squamous cell carcinoma (ESCC), a suitable setting for epidemiological studies. Hence, comparing the lifestyle, dietary habits and gene pools between the three regions will help in elucidation of ESCC etiology further. Therefore, to assess the possibility of conducting a larger case control study, we carried out a feasibility study to identify the collaborators as well as to explore patient referral systems and available research facilities in the state.
We found conducting good cancer molecular epidemiology studies is difficult due to lack of proper research facilities and favourable administrative guidelines. The appropriate storage, transportation and analyses facilities of biological specimens for genome-wide association study and assessment of nutrition and exposure markers are unavailable or not sufficiently developed. Guidelines that can encourage scientific collaborations within the country seem unavailable. However, the administrative guidelines available under which the export of biological specimens out of India for analysis seems impossible. Consequently, Indian researchers are unable to collaborate with foreign scientists and render state of art research facilities inaccessible to them. Scientists in other parts of India may also confront with most of these impediments.
The study found that for conducting conclusive molecular epidemiological studies in India, referral system in hospitals is not systematic, scientific research facilities are inadequate as well as the guidelines for foreign collaboration are not favourable.
Electronic supplementary material
The online version of this article (doi:10.1186/s40064-015-1046-z) contains supplementary material, which is available to authorized users.
Feasibility study; Research limitations; Collaboration; ESCC; Kashmir; India
Gastric cancer (GC) is the world’s fifth most common cancer, and the third leading cause of cancer-related death. Over 70% of incident cases and deaths occur in developing countries. We explored whether disparities in access to improved drinking water sources were associated with GC risk in the Golestan Gastric Cancer Case Control Study.
Methods and Findings
306 cases and 605 controls were matched on age, gender, and place of residence. We conducted unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CI), adjusted for age, gender, ethnicity, marital status, education, head of household education, place of birth and residence, homeownership, home size, wealth score, vegetable consumption, and H. pylori seropositivity. Fully-adjusted ORs were 0.23 (95% CI: 0.05–1.04) for chlorinated well water, 4.58 (95% CI: 2.07–10.16) for unchlorinated well water, 4.26 (95% CI: 1.81–10.04) for surface water, 1.11 (95% CI: 0.61–2.03) for water from cisterns, and 1.79 (95% CI: 1.20–2.69) for all unpiped sources, compared to in-home piped water. Comparing unchlorinated water to chlorinated water, we found over a two-fold increased GC risk (OR 2.37, 95% CI: 1.56–3.61).
Unpiped and unchlorinated drinking water sources, particularly wells and surface water, were significantly associated with the risk of GC.
Cardiovascular diseases (CVD) are becoming major causes of death in developing countries. Risk scoring systems for CVD are needed to prioritize allocation of limited resources. Most of these risk score algorithms have been based on a long array of risk factors including blood markers of lipids. However, risk scoring systems that solely use office-based data, not including laboratory markers, may be advantageous. In the current analysis, we validated the office-based Framingham risk scoring system in Iran.
The study used data from the Golestan Cohort in North-East of Iran. The following risk factors were used in the development of the risk scoring method: sex, age, body mass index, systolic blood pressure, hypertension treatment, current smoking, and diabetes. Cardiovascular risk functions for prediction of 10-year risk of fatal CVDs were developed.
A total of 46,674 participants free of CVD at baseline were included. Predictive value of estimated risks was examined. The resulting Area Under the ROC Curve (AUC) was 0.774 (95% CI: 0.762-0.787) in all participants, 0.772 (95% CI: 0.753-0.791) in women, and 0.763 (95% CI: 0.747-0.779) in men. AUC was higher in urban areas (0.790, 95% CI: 0.766-0.815). The predicted and observed risks of fatal CVD were similar in women. However, in men, predicted probabilities were higher than observed.
The AUC in the current study is comparable to results of previous studies while lipid profile was replaced by body mass index to develop an office-based scoring system. This scoring algorithm is capable of discriminating individuals at high risk versus low risk of fatal CVD.
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.
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 enzyme-linked immunosorbent assays. ESD was determined by chromoendoscopy with biopsy.
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 β-diversity matrix (pairwise difference in microbiota), and observed significant correlations between PC1, PC3 and PGI/II (P=0.004, 0.009 respectively), and between PC1 and ESD (P=0.003).
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).
microbiota; gastric cancer; esophageal squamous cell carcinoma; esophageal squamous dysplasia; serum pepsinogen I/pepsinogen II ratio
Objective To investigate the impact of smoking and smoking cessation on cardiovascular mortality, acute coronary events, and stroke events in people aged 60 and older, and to calculate and report risk advancement periods for cardiovascular mortality in addition to traditional epidemiological relative risk measures.
Design Individual participant meta-analysis using data from 25 cohorts participating in the CHANCES consortium. Data were harmonised, analysed separately employing Cox proportional hazard regression models, and combined by meta-analysis.
Results Overall, 503 905 participants aged 60 and older were included in this study, of whom 37 952 died from cardiovascular disease. Random effects meta-analysis of the association of smoking status with cardiovascular mortality yielded a summary hazard ratio of 2.07 (95% CI 1.82 to 2.36) for current smokers and 1.37 (1.25 to 1.49) for former smokers compared with never smokers. Corresponding summary estimates for risk advancement periods were 5.50 years (4.25 to 6.75) for current smokers and 2.16 years (1.38 to 2.39) for former smokers. The excess risk in smokers increased with cigarette consumption in a dose-response manner, and decreased continuously with time since smoking cessation in former smokers. Relative risk estimates for acute coronary events and for stroke events were somewhat lower than for cardiovascular mortality, but patterns were similar.
Conclusions Our study corroborates and expands evidence from previous studies in showing that smoking is a strong independent risk factor of cardiovascular events and mortality even at older age, advancing cardiovascular mortality by more than five years, and demonstrating that smoking cessation in these age groups is still beneficial in reducing the excess risk.
Observational studies revealed a relationship between changes in gastric mucosa and risk of esophageal squamous cell carcinoma (ESCC) which suggested a possible role for gastric microbiota in ESCC carcinogenesis. In this study we aimed to compare pattern of gastric corpus microbiota in ESCC with normal esophagus. Cases were included subjects with early ESCC (stage I–II) and esophageal squamous dysplasia (ESD) as the cancer precursor. Control groups included age and sex-matched subjects with mid-esophagus esophagitis (diseased-control), and histologically normal esophagus (healthy-control). DNA was extracted from snap-frozen gastric corpus tissues and 16S rRNA was sequenced on GS-FLX Titanium. After noise removal, an average of 3004 reads per sample was obtained from 93 subjects. We applied principal coordinate analysis to ordinate distances from beta diversity data. Pattern of gastric microbiota using Unifrac (p = 0.004) and weighted Unifrac distances (p = 0.018) statistically varied between cases and healthy controls. Sequences were aligned to SILVA database and Clostridiales and Erysipelotrichales orders were more abundant among cases after controling for multiple testing (p = 0.011). No such difference was observed between mid-esophagitis and healthy controls. This study is the first to show that composition of gastric corpus mucosal microbiota differs in early ESCC and ESD from healthy esophagus.
We performed a multistage genome-wide association study (GWAS) including 7,683 individuals with pancreatic cancer and 14,397 controls of European descent. Four new loci reached genome-wide significance: rs6971499 at 7q32.3 (LINC-PINT; per-allele odds ratio [OR] = 0.79; 95% confidence interval [CI] = 0.74–0.84; P = 3.0×10−12), rs7190458 at 16q23.1 (BCAR1/CTRB1/CTRB2; OR = 1.46; 95% CI = 1.30–1.65; P = 1.1×10−10), rs9581943 at 13q12.2 (PDX1; OR = 1.15; 95% CI = 1.10–1.20; P = 2.4×10−9), and rs16986825 at 22q12.1 (ZNRF3; OR = 1.18; 95% CI = 1.12–1.25; P = 1.2×10−8). An independent signal was identified in exon 2 of TERT at the established region 5p15.33 (rs2736098; OR = 0.80; 95% CI = 0.76–0.85; P = 9.8×10−14). We also identified a locus at 8q24.21 (rs1561927; P = 1.3×10−7) that approached genome-wide significance located 455 kb telomeric of PVT1. Our study has identified multiple new susceptibility alleles for pancreatic cancer worthy of follow-up studies.
We conducted a joint (pooled) analysis of three genome-wide association studies (GWAS) 1-3 of esophageal squamous cell carcinoma (ESCC) in ethnic Chinese (5,337 ESCC cases and 5,787 controls) with 9,654 ESCC cases and 10,058 controls for follow-up. In a logistic regression model adjusted for age, sex, study, and two eigenvectors, two new loci achieved genome-wide significance, marked by rs7447927 at 5q31.2 (per-allele odds ratio (OR) = 0.85, 95% CI 0.82-0.88; P=7.72x10−20) and rs1642764 at 17p13.1 (per-allele OR= 0.88, 95% CI 0.85-0.91; P=3.10x10−13). rs7447927 is a synonymous single nucleotide polymorphism (SNP) in TMEM173 and rs1642764 is an intronic SNP in ATP1B2, near TP53. Furthermore, a locus in the HLA class II region at 6p21.32 (rs35597309) achieved genome-wide significance in the two populations at highest risk for ESSC (OR=1.33, 95% CI 1.22-1.46; P=1.99x10−10). Our joint analysis identified new ESCC susceptibility loci overall as well as a new locus unique to the ESCC high risk Taihang Mountain region.
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.
Gastric cancer; gastric cardia; gastric noncardia; Fas signaling; genetic variants; GWAS; single nucleotide polymorphisms; pathway genes
A few studies have shown an association between blood group alleles and vascular disease, including atherosclerosis, which is thought to be due to the higher level of von Willebrand factor in these individuals and the association of blood group locus variants with plasma lipid levels. No large population-based study has explored this association with overall and cause-specific mortality.
We aimed to study the association between ABO blood groups and overall and cause-specific mortality in the Golestan Cohort Study. In this cohort, 50,045 people 40- to 70-years old were recruited between 2004 and 2008, and followed annually to capture all incident cancers and deaths due to any cause. We used Cox regression models adjusted for age, sex, smoking, socioeconomic status, ethnicity, place of residence, education and opium use.
During a total of 346,708 person-years of follow-up (mean duration 6.9 years), 3,623 cohort participants died. Non-O blood groups were associated with significantly increased total mortality (hazard ratio (HR) = 1.09; 95% confidence interval (CI): 1.01 to 1.17) and cardiovascular disease mortality (HR = 1.15; 95% CI: 1.03 to 1.27). Blood group was not significantly associated with overall cancer mortality, but people with group A, group B, and all non-O blood groups combined had increased risk of incident gastric cancer. In a subgroup of cohort participants, we also showed higher plasma total cholesterol and low-density lipoprotein (LDL) in those with blood group A.
Non-O blood groups have an increased mortality, particularly due to cardiovascular diseases, which may be due to the effect of blood group alleles on blood biochemistry or their effect on von Willebrand factor and factor VIII levels.
Please see related commentary 10.1186/s12916-014-0250-y.
Blood group; ABO; Rh; Mortality; Cancer; Cardiovascular disease
Maté tea is non-alcoholic infusion widely consumed in southern South America, and may increase risk of esophageal squamous cell carcinoma (ESCC) and other cancers due to polycyclic aromatic hydrocarbons and/or thermal injury.
We pooled two case-control studies: a 1988–2005 Uruguay study and a 1986–1992 multinational study in Argentina, Brazil, Paraguay and Uruguay, including 1,400 cases and 3,229 controls. We computed odds ratios (OR) and fitted a linear excess odds ratio (EOR) model for cumulative maté consumption in liters/day-year (LPDY).
The adjusted OR for ESCC with 95% confidence interval (CI) by ever compared with never use of maté was 1.60 (1.2,2.2). ORs increased linearly with LPDY (test of non-linearity, P=0.69). The estimate of slope (EOR/LPDY) was 0.009 (0.005,0.014) and did not vary with daily intake, indicating maté intensity did not influence the strength of association. EOR/LPDY estimates for consumption at warm, hot and very hot beverage temperatures were 0.004 (−0.002,0.013), 0.007 (0.003,0.013) and 0.016 (0.009,0.027), respectively, and differed significantly (P<0.01). EOR/LPDY estimates were increased in younger (<65) individuals and never alcohol drinkers, but these evaluations were post hoc, and were homogeneous by sex.
ORs for ESCC increased linearly with cumulative maté consumption and were unrelated to intensity, so greater daily consumption for shorter duration or lesser daily consumption for longer duration resulted in comparable ORs. The strength of association increased with higher mate temperatures.
Increased understanding of cancer risks with maté consumption enhances the understanding of the public health consequences given its purported health benefits.
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.
stomach neoplasms; cohort studies; prospective studies; hormones
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.
Microbiota; Oral health; Dental caries; Periodontitis; Bleeding on probe; Attachment loss
Stroke is the leading cause of death in Linxian, China. Although there is evidence of DNA damage in experimental stroke, no data exist on DNA repair and stroke in human populations.
To assess the risk of stroke conferred by polymorphisms in the DNA repair genes, XRCC1, XPD23 and APE/ref‐1 in a cohort of individuals originally assembled as subjects in two cancer prevention trials in Linxian, China.
The subjects for this prospective study were sampled from a cohort of 4005 eligible subjects who were alive and cancer free in 1991 and had blood samples available for DNA extraction. Using real‐time Taqman analyses, all incident cases of stroke (n = 118) that developed from May 1996, and an age‐ and a sex‐stratified random sample (n = 454) drawn from all eligible subjects were genotyped. Cox proportional hazards models were used to estimate relative risks (RRs) and 95% CIs.
No association was observed between polymorphisms in APE/ref‐1 codon 148 and XRCC1*6 codon 194, and stroke. Polymorphisms in XRCC1*10 codon 399 were associated with a significantly reduced risk of stroke (RR 0.59, 95% CI 0.36 to 0.96, p = 0.033), whereas XPD23 codon 312 was associated with a significantly increased risk of stroke (RR 2.18, 95% CI 1.14 to 4.17, p = 0.010).
Polymorphisms in DNA repair genes may be important in the aetiology of stroke. These data should stimulate research on DNA damage and repair in stroke.
Upper gastrointestinal (GI) cancers of the stomach and esophagus have high incidence and mortality worldwide, but they are uncommon in Western countries. Little information exists on the association between vitamin D and risk of upper GI cancers. This study examined the association between circulating 25-hydroxyvitamin D (25(OH)D) and upper GI cancer risk in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. Concentrations of 25(OH)D were measured from 1,065 upper GI cancer cases and 1,066 age-, sex-, race-, and season-of blood draw–matched controls from 8 prospective cohort studies. In multivariate-adjusted models, circulating 25(OH)D concentration was not significantly associated with upper GI cancer risk. Subgroup analysis by race showed that among Asians, but not Caucasians, lower concentrations of 25(OH)D (<25 nmol/L) were associated with a statistically significant decreased risk of upper GI cancer (reference: 50–<75 nmol/L) (odds ratio = 0.53, 95% confidence interval: 0.31, 0.91; P trend = 0.003). Never smokers with concentrations of <25 nmol/L showed a lower risk of upper GI cancers (odds ratio = 0.55, 95% confidence interval: 0.31, 0.96). Subgroup analyses by alcohol consumption produced opposing trends. Results do not support the hypothesis that interventions aimed at increasing vitamin D status would lead to a lower risk of these highly fatal cancers.
case-control studies; cohort studies; esophageal neoplasms; prospective studies; stomach neoplasms; vitamin D
It is hypothesized that poor zinc nutritional status is associated with an increased risk of esophageal cancer (EC), but current evidence is contradictory. Since some factors may influence zinc absorption, its status may be better evaluated thorough biomarkers. The objectives of this study were to perform a systematic review on the association of zinc biomarkers with EC in observational studies and to evaluate the efficacy of zinc supplements in preventing EC in randomized trials.
The MEDLINE database was searched in December 2013 for studies written in English with relevant keywords. Articles which met inclusion criteria were included in this study.
Eleven observational studies that measured zinc biomarkers and eight randomized trials which evaluated supplements containing zinc, met our inclusion criteria. The majority of studies suggested that higher zinc status was inversely associated with EC risk.
Most of the evidence for this hypothesis comes from case-control studies, which may introduce bias. Cohort studies are needed to establish whether poor zinc status is associated with increased risk for EC. Findings from trials are inconclusive as there is no data from single agent trials. However, the evidence is not still strong enough to conclude a protective role of zinc in EC.
Zinc; Esophageal cancer; Minerals; Systematic review
Several epidemiologic studies have suggested an inverse association between female reproductive factors and risk of esophageal squamous cell carcinoma (ESCC), but the evidence is not conclusive. We investigated the association of the number of pregnancies, live-births, and miscarriages/stillbirths in women and the association of the number of children in both sexes with ESCC risk in Golestan Province, a high-risk area in Iran.
Data from 297 histopathologically confirmed ESCC cases (149 women) and 568 controls (290 women) individually matched to cases for age, sex, and neighborhood of residence were included in this analysis. Conditional logistic regression was used to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs).
The average numbers of live-births and miscarriages/stillbirths among controls were 8.2 and 0.8, respectively. Women with 6 or more live-births were at approximately one-third the risk of ESCC as those with 0–3 live-births; the OR (95% CI) for having 6–7 live-births was 0.33 (0.12–0.92). In contrast, the number of miscarriages/stillbirths was associated with an increase in ESCC risk. The OR (95% CI) for ≥ 3 versus no miscarriages/stillbirths was 4.43 (2.11–9.33). The number of children in women was suggestive an inverse association with ESCC, but this association was not statistically significant; in men, no association was seen.
The findings of this study support a protective influence of female hormonal factors on ESCC risk. However, further epidemiological and mechanistic studies are needed to prove a protective association.
case-control study; esophageal cancer; miscarriage; parity; reproductive; squamous cell carcinoma
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.
food habits; esophageal neoplasms; stomach neoplasms
This study tests the hypothesis that prediagnostic serum levels of 20 cancer-associated inflammatory biomarkers correlate directly with future development of head and neck, esophageal, and lung cancers in a high-risk prospective cohort. This is a nested case–control pilot study of subjects enrolled in the Golestan Cohort Study, an ongoing epidemiologic project assessing cancer trends in Golestan, Iran. We measured a panel of 20 21cytokines, chemokines, and inflammatory molecules using Luminex technology in serum samples collected 2 or more years before cancer diagnosis in 78 aerodigestive cancer cases and 81 controls. Data was analyzed using Wilcoxon rank sum test, odds ratios, receiver operating characteristic areas of discrimination, and multivariate analysis. Biomarkers were profoundly and globally elevated in future esophageal and lung cancer patients compared to controls. Odds ratios were significant for association between several biomarkers and future development of esophageal cancer, including interleukin-1Rα (IL-1Ra; 35.9), interferon α2 (IFN-a2; 34.0), fibroblast growth factor-2 (FGF-2; 17.4), and granulocyte/macrophage colony-stimulating factor (GM-CSF; 17.4). The same pattern was observed among future lung cancer cases for G-CSF (27.7), GM-CSF (13.3), and tumor necrosis factor-α (TNF-a; 8.6). By contrast, the majority of biomarkers studied showed no significant correlation with future head and neck cancer development. This study provides the first direct evidence that multiple inflammatory biomarkers are coordinately elevated in future lung and esophageal cancer patients 2 or more years before cancer diagnosis.
Aerodigestive cancer; esophageal squamous cell carcinoma; head and neck squamous cell carcinoma; lung cancer; serum inflammatory biomarker