Is the Association Between Helicobacter pylori and Gastric Cancer Confined to CagA‐Positive Strains?

BACKGROUND: Infection with Helicobacter pylori is associated with an increased risk of gastric cancer. Several studies have indicated that the association differs with strain type. We aimed to find out if infection with strains lacking the virulence factor CagA is linked to gastric cancer risk. MATERIALS AND METHODS: In a hospital-based case-control study, we collected sera from 100 case patients with a newly diagnosed gastric adenocarcinoma and 96 control patients with diseases unrelated to H. pylori status. Antibodies to H. pylori were analyzed by enzyme-linked immunosorbent assay (ELISA), and antibodies to CagA were detected by immunoblot. Logistic regression was used to obtain odds ratios (ORs) as estimates of relative risk, adjusted for potential confounding. RESULTS: Among the case patients, 81% were ELISA positive and 86% had antibodies to CagA. The corresponding numbers among the controls were 58% and 55%, respectively. ELISA positivity was associated with an increased risk of gastric adenocarcinoma compared to ELISA negativity (OR for gastric cancer regardless of site 3.9, 95% CI 1.9-8.2). The OR was 7.4 (95% CI 3.3-16.6) for CagA-positive relative to CagA-negative subjects. Among ELISA-positive subjects the presence of CagA antibodies increased the risk 3.6 times (95% CI 1.2-11.1). ELISA-positive CagA-negative infections were associated with a fourfold increased risk (OR = 4.2, 95% CI 1.0-17.0) compared to no infection (ELISA-negative and CagA-negative). CONCLUSIONS: Although patients with antibodies to CagA have the greatest risk of developing gastric cancer, those with CagA-negative infections run a significantly greater risk than uninfected persons.     

Helicobacter pylori infection and gastroesophageal reflux in a population-based study (The HUNT Study)

BACKGROUND AND AIM: It has been suggested that Helicobacter pylori infection may prevent gastroesophageal reflux, possibly through gastric atrophy. Since, however, previous results are contradictory and no population-based studies are available, the relationship between H. pylori and reflux remains uncertain. The aim of this study was to investigate this relationship in a population-based, nested, case-control study. METHODS: From a cohort of 65,363 individuals, representing 71.2% of the adult population in the Norwegian county of Nord-Trondelag, we randomly selected 472 persons with recurrent reflux symptoms (cases) and 472 without such symptoms (controls). Occurrence of H. pylori and its virulence factor cagA was determined serologically, using an immunoblot assay. Gastric atrophy was assessed through serum levels of pepsinogen I. Odds ratios (OR) with 95% confidence intervals (CI), adjusted for potential confounding factors, represented relative risks. RESULTS: H. pylori infection was not associated with a decreased risk of reflux symptoms (OR 1.1, 95% CI 0.8-1.6), irrespective of positive cagA status (OR 1.1, 95% CI 0.8-1.5). Gastric atrophy reduced the risk of reflux symptoms (OR 0.2, 95% CI 0.0-0.6). Infection with H. pylori entailed a ninefold increase in the risk of gastric atrophy compared to non-infection (OR 8.9, 95% CI 2.0-39.9). CONCLUSIONS: H. pylori infection, irrespective of cagA status, did not affect the occurrence of reflux symptoms in this population-based setting. Infected individuals are at increased risk of gastric atrophy, which in turn reduces reflux symptoms, but due to the low frequency of gastric atrophy among infected individuals overall, there was no association with reflux symptoms on a population level.     

The XRCC1 399 glutamine allele is a risk factor for adenocarcinoma of the lung

Defects in the repair and maintenance of DNA increase risk for cancer. X-ray cross-complementing group 1 protein (XRCC1) is involved with the repair of DNA single-strand breaks. A nucleotide substitution of guanine to adenine leading to a non-conservative amino acid change was identified in the XRCC1 gene at codon 399 (Arg/Gln). This change is associated with higher levels of aflatoxin B1-adducts and glycophorin A somatic mutations. A case-control study was conducted to test the hypothesis that the 399Gln allele is positively associated with risk for adenocarcinoma of the lung. XRCC1 genotypes were assessed at codon 399 in 172 cases of lung adenocarcinoma and 143 cancer-free controls. Two ethnic populations were represented, non-Hispanic White and Hispanic. The distribution of XRCC1 genotypes differed between cases and controls. Among cases, 47.7% were Arg/Arg, 35.5% were Arg/Gln, and 16.9% were Gln/Gln. Among controls, XRCC1 allele frequencies were 45.5% for Arg/Arg, 44.8% for Arg/Gln, and 9.8% for Gln/Gln. Logistic regression analysis was used to assess the association between lung adenocarcinoma and the G/G genotype relative to the A/A or A/G genotypes. In non-Hispanic White participants, the lung cancer risk associated with the G/G genotype increased significantly after adjustment for age (OR=2.81; 95% CI, 1.2-7.9; P=0.03) and increased further after adjustment for smoking (OR=3.25; 95% CI, 1.2-10.7; P=0.03). Among all groups, a significant association was found between the G/G homozygote and lung cancer (OR=2.45; 95% CI, 1.1-5.8; P=0.03) after adjustment for age, ethnicity, and smoking. This study links a functional polymorphism in the critical repair gene XRCC1 to risk for adenocarcinoma of the lung.     

Pre-diagnostic circulating p53 autoantibodies and subsequent lung cancer risk in low-income African and European Americans

IntroductionMutations of the TP53 gene lead to the production of autoantibodies against p53, a major tumor suppressor protein. Although studies have indicated the association of p53 autoantibodies with human cancers, epidemiologic evidence on lung cancer is still lacking.MethodsIn this nested case-control study conducted within the Southern Community Cohort Study, we investigated the association of circulating p53 autoantibodies with the subsequent risk of developing lung cancer. Using blood samples collected prior to any cancer diagnosis from 295 cases and their individually matched controls, seroreactivity to p53 was assessed by fluorescent bead-based multiplex serology. Conditional logistic regression models were used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for lung cancer risk associated with p53 autoantibodies.ResultsAfter adjustment for potential confounders, p53 seropositivity was significantly associated with an increased risk of lung cancer (OR=2.98, 95 % CI: 1.10–8.06) among African Americans, but not among European Americans (OR=1.21, 95 % CI: 0.24–6.15). The positive associations were restricted to men (OR=4.59, 95 % CI: 1.30–16.16) and participants with a short interval (≤ 4 years) from blood collection to diagnosis (OR=4.30, 95 % CI: 1.33–13.89).ConclusionOur findings add to the evidence supporting p53 autoantibodies as a biomarker of lung cancer.     

上海市区女性肺癌的家族聚集性研究

我们利用在上海市区所开展的一项关于女性肺癌的较大规模人群基础上的病例对照研究资料,分析和评价了一级亲属患肺癌史者其在肺癌发生中的作用。文中重点分析了女性非吸烟者肺癌的材料。结果表明,先证者家系一级亲属患肺癌的风险性是对照组家系一级亲属的近3倍(OR=2.80,95% CI1.68-4.67)。对非吸烟先证者家系而言,比数比为2.62(95%CI1.52-4.5 2)。其中,腺癌、鳞癌、其他类和不明分类的肺癌的OR分别为2.79(95%CI 1.53-5.10)、3.88 (95%CI1.42-10.63)、1.26(95%CI0.27-6.01)、2.52 (95%CI1.16-5.49)。按年龄组分层分析的结果显示,35-59岁组与60-69岁组的比数比分别为4.01 (95%CI1.71-8.97)、 1.89(95%CI0.89-3.98)。非吸烟女性研究对象经多因素非条件logistic回归模型的分析后,比数比OR为2.71(95%CI1.54-4.76),有高度统计学意义。在该多变量回归模型的基础上估计的调整人群归因风险度为5.31%。 Abstract:The data set of a large population-based case-control study of female lung cancer conducted in Shanghai urban was used to investigate the contribution of lung cancer in first-degree relatives to lung cancer risk.The analysis in the paper is emphasized on non-smoking women.The results indicates that the risk of first-degree relatives with lung cancer is increased about 30fold(OR=2.80,95% CI:1.68-4.67),and for non-smoking probands the OR is 2.62(95% CI:1.52-4.52).The odds ratios of adeno-carcinoma,squamous cell carcinoma,others unknown of lung cancer are 2.79(95% CI:1.53-5.10),3.88(95% CI:1.42-10.63),1.26(95% CI:0.27-6.01),2.52(95% CI:1.16-5.49),respectively.For cases of age groups of 35 to 59 and 60 to 69 years of probands,with ORs of 4.01(95% CI:1.79-8.97)and 1.89(95% CI:0.89-3.98)respectively.The odds ratio from multivariable unconditional logistic regression is 2.71(95% CI:1.54-4.76).The estimation of adjusted population attributable risk is 5.31% based on the multivariable logistic regression model analysis.     

Polymorphisms of CHRNA5-CHRNA3-CHRNB4 Gene Cluster and NSCLC Risk in Chinese Population

AIM: To explore the potential association between single-nucleotide polymorphisms (SNPs) and haplotypes of the CHRNA5-CHRNA3-CHRNB4 gene cluster and the non-small cell lung cancer (NSCLC) susceptibility in never-smoking Chinese. METHODS: A case-control study was conducted with 200 NSCLC patients and 200 healthy controls, matched on age and sex. Five SNPs distributed in CHRNA5-CHRNA3-CHRNB4 gene cluster were selected for genotyping. The association between genotype and lung cancer risk was evaluated by computing the odds ratio (OR) and 95% confidence interval (CI) from multivariate unconditional logistic regression analyses with adjustment for gender and age. RESULTS: For CHRNA3 rs578776 status, data were available in 199 NSCLC patients and 199 controls. The G/G homozygote in CHRNB4 rs7178270 had a reduced risk of developing NSCLC (OR = 0.553; 95% CI = 0.309–0.989; P = .0437), especially squamous cell carcinoma (SQC) (OR = 0.344; 95% CI = 0.161–0.732; P = .0043), compared with those who carry at least one C allele (C/C and C/G). The polymorphisms of rs578776, rs938682, rs17486278, and rs11637635 were not significantly different between controls and cases or between controls and histologic subgroups, adenocarcinoma and SQC, respectively. CONCLUSIONS: In our study, we found that the SNP of CHRNB4 rs7178270 is significantly associated with reduced risk of NSCLC, especially with reduced risk of SQC in never-smoking Chinese population.     

Association between the OGG1 Ser326Cys and APEX1 Asp148Glu polymorphisms and lung cancer risk: a meta-analysis

The previous published data on the association between the 8-oxo-guanine glycosylase-1 (OGG1) and apurinic/apyrimidinic-endonuclease-1 (APEX1/APE1) polymorphisms and lung cancer risk remained controversial. Several polymorphisms in the OGG1 and APEX1 gene have been described, including the commonly occurring Ser326Cys in OGG1 and Asp148Glu in APEX1. This meta-analysis of literatures was performed to derive a more precise estimation of the relationship. A total of 37 studies were identified to the meta-analysis, including 9,203 cases and 10,994 controls for OGG1 Ser326Cys (from 25 studies) and 3,491 cases and 4,708 controls for APEX1 Asp148Glu (from 12 studies). When all the eligible studies were pooled into the meta-analysis of OGG1 Ser326Cys polymorphism, significantly increased lung cancer risk was observed in recessive model (OR?=?1.17, 95?% CI?=?1.03–1.33) and in additive model (OR?=?1.21, 95?% CI?=?1.03–1.42). In the stratified analysis, significantly increased risk of lung cancer was also observed on the population-based studies (recessive model: OR?=?1.26, 95?% CI?=?1.08–1.46, additive model: OR?=?1.42, 95?% CI?=?1.06–1.73) and non-smokers (dominant model: OR?=?1.20, 95?% CI?=?1.02–1.42, recessive model: OR?=?1.20, 95?% CI?=?1.02–1.40, additive model: OR?=?1.35, 95?% CI?=?1.08–1.68). Additionally, when one study was deleted in the sensitive analysis, the results of OGG1 Ser326Cys were changed in Asians (recessive model: OR?=?1.16, 95?% CI?=?1.06–1.27, additive model: OR?=?1.23, 95?% CI?=?1.09–1.38). When all the eligible studies were pooled into the meta-analysis of APEX1 Asp148Glu polymorphism, there was no evidence of significant association between lung cancer risk and APEX1 Asp148Glu polymorphism in any genetic model. In the stratified analysis, significantly decreased lung adenocarcinoma risk was observed in recessive model (OR?=?0.68, 95?% CI?=?0.48–0.97, P _h?=?0.475, I²?=?0.0?%). Additionally, when one study was deleted in the sensitive analysis, the results of APEX1 Asp148Glu were changed in Asians (recessive model: OR?=?1.21, 95?% CI?=?1.03–1.43) and smokers (dominant model: OR?=?1.62, 95?% CI?=?1.08–2.44, additive model: OR?=?1.37, 95?% CI?=?1.02–1.84). In summary, this meta-analysis indicates that OGG1 Ser326Cys show an increased lung cancer risk in Asians and non-smokers, APEX1 Asp148Glu polymorphism may be associated with decreased lung adenocarcinoma risk, and APEX1 Asp148Glu polymorphism show an increased lung cancer risk in Asians and smokers. However, a study with the larger sample size is needed to further evaluated gene-environment interaction on OGG1 Ser326Cys and APEX1 Asp148Glu polymorphisms and lung cancer risk.     

Professional exposure to goats increases the risk of pneumonic-type lung adenocarcinoma: results of the IFCT-0504-Epidemio study

Pneumonic-type lung adenocarcinoma (P-ADC) represents a distinct subset of lung cancer with specific clinical, radiological, and pathological features. Given the weak association with tobacco-smoking and the striking similarities with jaagsiekte sheep retrovirus (JSRV)-induced ovine pulmonary adenocarcinoma, it has been suggested that a zoonotic viral agent infecting pulmonary cells may predispose to P-ADC in humans. Our objective was to explore whether exposure to domestic small ruminants may represent a risk factor for P-ADC. We performed a multicenter case-control study recruiting patients with P-ADC as cases and patients with non-P-ADC non-small cell lung cancer as controls. A dedicated 356-item questionnaire was built to evaluate exposure to livestock. A total of 44 cases and 132 controls were included. At multivariate analysis, P-ADC was significantly more associated with female gender (Odds-ratio (OR)?=?3.23, 95% confidence interval (CI): 1.32-7.87, p?=?0.010), never-smoker status (OR?=?3.57, 95% CI: 1.27-10.00, p?=?0.015), personal history of extra-thoracic cancer before P-ADC diagnosis (OR?=?3.43, 95% CI: 1.10-10.72, p?=?0.034), and professional exposure to goats (OR?=?5.09, 95% CI: 1.05-24.69, p?=?0.043), as compared to other subtypes of lung cancer. This case-control suggests a link between professional exposure to goats and P-ADC, and prompts for further epidemiological evaluation of potential environmental risk factors for P-ADC.     

Genetic susceptibility and risk of gastric cancer in a human population of Cauca, Colombia

Gastric cancer (GC) is the main cause of mortality by cancer in Colombia. Glutathione S-transferase (GST) enzymes are involved in the detoxification of many environmental carcinogens. The homozygous deletions of glutathione S-transferase M1 (GSTM1-0) and glutathione S-transferase T1 (GSTT1-0) have been associated with several types of cancer. The risk to develop GC has been associated with environmental factors and Helicobacter pylori infection. The tumor necrosis factor (TNF-alpha) and its levels are increased in patients infected with H. pylori. A G/ A transition in the position -308 of the promoter of the TNF-alpha has been related in several studies to an increased expression of the gene and is associated with susceptibility to GC. The association of these polymorphisms with GC and the interaction with other risk factors (life style) were investigated. Blood samples were obtained from 46 GC patients and 96 controls. The logistic regression model was used to obtain the odds ratio (OR) and their 95% confidence intervals. These statistics established the association between the enzymatic polymorphisms and GC and between other independent factors and GC. The frequency of the TNF-alpha polymorphism in people infected with H. pylori was 18% in the GC population and 7% in the control group. This transition was not significantly associated with H. pylori infection and GC. The frequencies of the deletion polymorphisms for patients and controls were as follows: GSTM1 65.2% and 37.5%; GSTT1 17.4% and 14.6%. These results suggested that the GSTM1 deletion polymorphism was associated with an increased risk of gastric cancer (OR of 5.5; 95%CI, 1.7-17.2). Furthermore, other risk factors such as H. pylori infection (OR 5.58, CI 1.8-17.2), smoking (OR 6.70, CI 2.2-20.3) and alcohol intake (OR 3.27, CI 1.1-9.4) were associated with GC.     

LTA 252GG and GA Genotypes are Associated with Diffuse-Type Noncardia Gastric Cancer Risk in the Japanese Population

Background:  There are limited numbers of reports on the association of lymphotoxin-alpha ( LTA ) genotypes with gastric cancer.
Methods:  A nested case–control study was carried out in the longitudinal cohort of atomic bomb survivors using stored sera before diagnosis (mean, 2.3 years) and blood cells. Enrolled were 287 cases with noncardia gastric cancer of diffuse and intestinal types and three controls per case selected from cohort members matched on age, gender, city, and time and type of serum storage and counter-matched on radiation dose.
Results:  LTA 252GG and GA genotypes were associated with the prevalence of Helicobacter pylori IgG seropositivity and higher antibody titer against H. pylori cytotoxin-associated gene A (CagA) protein in controls and they were an independent risk factor for noncardia gastric cancer of diffuse type (RR = 2.8 (95% CI: 1.3–6.3), p  =   .01, and RR = 2.7 (95% CI: 1.5–4.8), p  <   .001), but not for intestinal type, after adjusting for H. pylori IgG seropositivity, CagA antibody titers, chronic atrophic gastritis, smoking, and radiation dose. Cessation of smoking (RR = 0.4 (95% CI: 0.2–0.7), p  <   .001) and never smoking (RR = 0.4 (95% CI: 0.3–0.6), p  <   .001) were both protective for future noncardia gastric cancer. Radiation dose was associated with noncardia gastric cancer in subjects with both the LTA 252G -allele and never smoking/quit smoking histories (RR = 3.8 (95% CI: 1.7–5.9), p  =   .009).
Conclusion:  The LTA 252 genotype is associated with noncardia gastric cancer of diffuse type in Japan and interacted with radiation dose.     

Alcohol consumption and lung cancer risk: A pooled analysis from the International Lung Cancer Consortium and the SYNERGY study

BackgroundThere is inadequate evidence to determine whether there is an effect of alcohol consumption on lung cancer risk. We conducted a pooled analysis of data from the International Lung Cancer Consortium and the SYNERGY study to investigate this possible association by type of beverage with adjustment for other potential confounders.MethodsTwenty one case-control studies and one cohort study with alcohol-intake data obtained from questionnaires were included in this pooled analysis (19,149 cases and 362,340 controls). Adjusted odds ratios (OR) or hazard ratios (HR) with corresponding 95% confidence intervals (CI) were estimated for each measure of alcohol consumption. Effect estimates were combined using random or fixed-effects models where appropriate. Associations were examined for overall lung cancer and by histological type.ResultsWe observed an inverse association between overall risk of lung cancer and consumption of alcoholic beverages compared to non-drinkers, but the association was not monotonic. The lowest risk was observed for persons who consumed 10–19.9 g/day ethanol (OR vs. non-drinkers = 0.78; 95% CI: 0.67, 0.91), where 1 drink is approximately 12–15 g. This J-shaped association was most prominent for squamous cell carcinoma (SCC). The association with all lung cancer varied little by type of alcoholic beverage, but there were notable differences for SCC. We observed an association with beer intake (OR for ≥20 g/day vs nondrinker = 1.42; 95% CI: 1.06, 1.90).ConclusionsWhether the non-monotonic associations we observed or the positive association between beer drinking and squamous cell carcinoma reflect real effects await future analyses and insights about possible biological mechanisms.     

Job strain and risk of esophageal and cardia cancers

BackgroundFew studies have investigated work-related stress in relation to esophageal or cardia cancers.MethodsOur nationwide Swedish population-based case-control study included 189 and 262 esophageal and cardia adenocarcinoma cases respectively, 167 esophageal squamous-cell carcinoma cases and 820 controls. We derived each study participant's occupation of longest duration from occupational histories and applied a psychosocial job-exposure matrix. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using conditional logistic regression, in multivariable models.ResultsJob strain was positively associated with risk of esophageal adenocarcinoma (OR 3.2, 95% CI 1.0–9.8) and squamous-cell carcinoma (OR 4.0, 95% CI 1.6–10.5), but not with cardia adenocarcinoma. No associations regarding demands, control, social support or iso strain were observed, except for a positive association between high control and risk of esophageal squamous-cell carcinoma (OR 1.5, 95% CI 1.0–2.3).ConclusionJob strain seems to increase the risk of both histological types of esophageal cancer.     

Genetic variant in TP63 on locus 3q28 is associated with risk of lung adenocarcinoma among never-smoking females in Asia

A recent genome-wide association study (GWAS) of subjects from Japan and South Korea reported a novel association between the TP63 locus on chromosome 3q28 and risk of lung adenocarcinoma (p = 7.3 × 10(-12)); however, this association did not achieve genome-wide significance (p ≤ 10(-7)) among never-smoking males or females. To determine if this association with lung cancer risk is independent of tobacco use, we genotyped the TP63 SNPs reported by the previous GWAS (rs10937405 and rs4488809) in 3,467 never-smoking female lung cancer cases and 3,787 never-smoking female controls from 10 studies conducted in Taiwan, Mainland China, South Korea, and Singapore. Genetic variation in rs10937405 was associated with risk of lung adenocarcinoma [n = 2,529 cases; p = 7.1 × 10(-8); allelic risk = 0.80, 95% confidence interval (CI) = 0.74-0.87]. There was also evidence of association with squamous cell carcinoma of the lung (n = 302 cases; p = 0.037; allelic risk = 0.82, 95% CI = 0.67-0.99). Our findings provide strong evidence that genetic variation in TP63 is associated with the risk of lung adenocarcinoma among Asian females in the absence of tobacco smoking.     

The presence of the UGT2B17 gene is associated with lung cancer in male Chinese Han smokers

The genetic impact of UGT2B17 gene copy number variation (CNV) on tobacco-smoking related cancers is of interest since this enzyme plays an important role in glucuronidation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a major metabolite from the nicotine-derived tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). This is an important mechanism for NNK detoxification. The UGT2B17 gene varies in copy number from zero to two per individual in humans and this CNV was genotyped in 148 lung cancer and 92 control Chinese Han samples by a PCR-based method. The frequency of the UGT2B17 undeleted allele was higher in lung cancer patients than in controls but not significantly so (p = 0.042, OR 1.6; 95% CI: 0.97–2.57); however, in smokers with lung cancer its frequency is significantly higher than in controls, (p = 0.016, OR 1.8; 95% CI: 1.08–3.18). The undeleted allele was also significantly higher in the male lung cancer group (p = 0.015, OR 1.86; 95% CI: 1.09–3.16), and even higher in the male smoker lung cancer group (p = 0.004, OR 2.23; 95% CI: 1.27–3.89). In subsets of the male smoker lung cancer group defined by their histopathology, the undeleted allele was significantly higher in squamous cell carcinoma (p = 0.026, OR 2.09; 95% CI: 1.06–4.10). These results show that UGT2B17 copy number is associated with male smoker lung cancer in China, especially squamous cell carcinoma.     

Association of Helicobacter pylori-related distal gastric cancer with the HLA class II gene DQB10602 and cagA strains in a southern European population

BACKGROUND: Distinct human leukocyte antigen (HLA)-DQ genes have been associated with an increased or reduced risk for gastric cancer, but its association with Helicobacter pylori status is controversial. In the present study we evaluated the influence of host HLA DQA1 and DQB1 loci, H. pylori genotype, and socio-economic factors on predicting H. pylori-associated distal gastric cancer in a southern European population. MATERIAL AND METHODS: In a prospective case-control (1 : 2) study, 42 patients with H. pylori-associated distal gastric cancer were matched by age (+/-5 years) and gender to 84 patients with H. pylori-associated benign gastroduodenal disease (controls). The level of education received, smoking status, alcohol consumption, origin and familial history of gastric cancer were registered at inclusion. HLA DQA1 and DQB1 typing and H. pylori genotyping were determined from endoscopic gastric mucosal biopsies. RESULTS: Compared with control patients, a positive association with cagA(+) strains (p < .002) and a negative association with vacA-s2 strains (p < .02) was found in patients with distal gastric cancer. At the DQB1 locus, the (*)0602 allele was more frequent in distal gastric cancer than in controls (26.2% vs. 4.8%; p < .005). After correction for multiple comparisons (exact multiple regression analysis) the cagA(+) status and the DQB1(*)0602 allele were associated with an increased distal gastric cancer risk (OR 3.7; 95% CI = 1.33-12.26 and OR 4.82; 95% CI = 1.24-19.83, respectively) whereas the vacA-s2 status was associated with a decreased risk (OR 0.33; 95% CI = 0.10-0.94). CONCLUSION: Our findings suggest that in the H. pylori-infected southern European population, the cagA genotype and the HLA-DQB1(*)0602 gene confer an increased risk for distal gastric cancer.     

Epidemiological study on Helicobacter pylori infection and extragastroduodenal disorders in Polish population.

An association between Helicobacter pylori (H. pylori) infection and extragastroduodenal disorders (EGDD) is still not clear. The aim of the study was to investigate the relationship between H. pylori infection and the symptoms of coronary artery disease (CAD), facial dermatological changes (FDC), gastroesophageal reflux diseases (GERD), and periodontal diseases (PD) in Polish population. The study was performed between 1996-1999 year on 7,060 adult inhabitants of municipal area of Krakow (aged 18-76, mean 46.3 year; 55.8% female, 44.2% male): 2,204 subjects with EGDD and 4,856 without symptoms of EGDD. Each patient responded to a detailed questionnaire under supervision of medical staff. The H. pylori status was assessed non-invasively using urea breath test (UBT) with capsulated low-dose 13C-UBT (38 mg). Exclusion criteria were: recent H. pylori eradication, treatment with PPI, bismuth and/or antibiotics in the last 4 weeks. Four groups of cases with EGDD symptoms were selected. Within each group exclusively only one of studied symptoms was recorded. The study included 328, 138, 688, and 1,050 patients with CAD, FDC, GERD and PD, respectively. For each studied group an age and sex-matched asymptomatic controls were selected (897, 387, 1,083, and 2,489 control patients). Results: Overall H. pylori infection rate was 69,9% (in 71.4% of 2,204 cases and in 69.31% of 4,856 controls). In CAD group: 68% of 328 cases were H. pylori (+ve) vs. 70% H. pylori (+ve) of 897 controls. An association was not significant: OR = 0.93 (95% CI, 0.72-1.20). In 138 of FDC cases, 59% were H. pylori (+ve) vs. 71% H. pylori (+ve) in 387 controls showing the lack of positive association; OR = 0.60 (95% CI, 0.42-0.87). In GERD, 69% of 688 cases were H. pylori (+ve) vs. 73% of 1,083 H. pylori (+ve) controls and negative association was observed; OR=0.80 (95% CI, 0.65-1.00). In 1,050 of PD cases 75% were H. pylori (+ve) vs. 68% H. pylori (+ve) of 2,489 controls; positive association was significant; OR = 1.4 (95% CI, 1.16-1.68). We conclude that in the studied Polish population, no positive association exists between H. pylori positivity and CAD, FDC or GERD possibly due very high overall H. pylori infection rate. The only positive link observed between H. pylori infection and periodontal disease may reflect direct "in situ" H. pylori pathological action of H. pylori in oral cavity. It is not excluded that periodontal diseases may facilitate the H. pylori oro-gastric transmission and colonisation of the bacteria in the digestive tract.     

Polymorphisms in insulin-related genes predispose to specific KRAS2 and TP53 mutations in colon cancer

Risk factors for colon cancer may not only influence the overall risk of cancer but also the risk for specific types of mutations. We evaluated the effect of polymorphisms in four insulin-related genes (G972R in IRS1, G1057D in IRS2, a CA repeat in IGFI and an A/C polymorphism at -202 of IGFBP3) on the risk of microsatellite instability and KRAS2 and TP53 mutations in a population-based set of 1788 cases of colon cancer and 1981 controls. The GR/RR IRS1 genotypes were associated with an increased risk of colon cancers with the KRAS2 G12D mutation (OR 2.3, 95% CI 1.5, 3.5 versus controls, OR 1.7, 95% CI 1.1, 2.6 versus KRAS2 wild type), the "no 192" IGFI genotype increased the risk of the KRAS2 G13D mutation (OR 2.3, 95% CI 1.2, 4.2 versus controls, OR 2.1, 95% CI 1.1, 4.0 versus wild type), and the DD IRS2 genotype increased the risk of the G12V KRAS2 mutation (OR 1.8, 95% CI 0.9, 3.5 versus controls, OR 2.0, 95% CI 1.0, 4.0 versus wild type). Polymorphisms in IRS1 and IGF1 were also associated with an approximately two-fold increased risk of specific TP53 mutations relative to controls without cancer. We conclude that polymorphisms in some insulin-related genes are associated with an increased risk of colon cancer with specific KRAS2 and TP53 mutations, implying a link between these genetic changes and specific mutational pathways in carcinogenesis.     

A Genome-wide Association Study of Lung Cancer Identifies a Region of Chromosome 5p15 Associated with Risk for Adenocarcinoma

Three genetic loci for lung cancer risk have been identified by genome-wide association studies (GWAS), but inherited susceptibility to specific histologic types of lung cancer is not well established. We conducted a GWAS of lung cancer and its major histologic types, genotyping 515,922 single-nucleotide polymorphisms (SNPs) in 5739 lung cancer cases and 5848 controls from one population-based case-control study and three cohort studies. Results were combined with summary data from ten additional studies, for a total of 13,300 cases and 19,666 controls of European descent. Four studies also provided histology data for replication, resulting in 3333 adenocarcinomas (AD), 2589 squamous cell carcinomas (SQ), and 1418 small cell carcinomas (SC). In analyses by histology, rs2736100 (TERT), on chromosome 5p15.33, was associated with risk of adenocarcinoma (odds ratio [OR] = 1.23, 95% confidence interval [CI] = 1.13–1.33, p = 3.02 × 10⁻⁷), but not with other histologic types (OR = 1.01, p = 0.84 and OR = 1.00, p = 0.93 for SQ and SC, respectively). This finding was confirmed in each replication study and overall meta-analysis (OR = 1.24, 95% CI = 1.17–1.31, p = 3.74 × 10⁻¹⁴ for AD; OR = 0.99, p = 0.69 and OR = 0.97, p = 0.48 for SQ and SC, respectively). Other previously reported association signals on 15q25 and 6p21 were also refined, but no additional loci reached genome-wide significance. In conclusion, a lung cancer GWAS identified a distinct hereditary contribution to adenocarcinoma.     

Association between haplotypes of manganese superoxide dismutase (SOD2), smoking, and lung cancer risk

Tobacco smoke contains high concentrations of reactive oxygen species (ROS) that can damage DNA, proteins, and lipids. Manganese superoxide dismutase (SOD2) catalyzes the dismutation of superoxide radicals into hydrogen peroxide and protects against oxidative stress in lung tissues. Three tagSNPs were identified in one block of high linkage disequilibrium that spans the entire SOD2 gene and 5-kb promoter region. These tagSNPs, representing four haplotypes (TAA, TCA, TCG, CCG), were genotyped in 372 lung cancer cases and 605 controls. There was no association between the haplotype frequencies and the overall lung cancer risk. The TCG haplotype (6% in controls) was significantly associated with a lower risk of lung cancer in light smokers (相似文献