Increased risk of noncardia gastric cancer associated with proinflammatory cytokine gene polymorphisms

BACKGROUND & AIMS: Genetic variations in proinflammatory and anti-inflammatory cytokine genes influence individual response to carcinogenic exposures. Polymorphisms in interleukin (IL)-1 beta and its endogenous receptor antagonist are associated with risk of Helicobacter pylori-related gastric cancer. The aim of this study was to evaluate the role of proinflammatory cytokine gene polymorphisms in gastric and esophageal cancers defined by anatomic subsite. METHODS: We assessed polymorphisms of the IL-1 gene cluster and 4 other cytokine genes in a population-based case-control study of upper gastrointestinal cancers, including gastric cardia (n = 126) and noncardia adenocarcinoma (n = 188), esophageal squamous cell carcinoma (n = 53), and adenocarcinoma (n = 108), and frequency-matched controls (n = 212). ORs for the different cancers were computed from logistic regression models adjusted for potential confounding factors. RESULTS: Proinflammatory genotypes of tumor necrosis factor alpha and IL-10 were each associated with more than doubling of the risk of noncardia gastric cancer. Carriage of multiple proinflammatory polymorphisms of IL-1B(o) IL-1 receptor antagonist, tumor necrosis factor A, and IL-10 conferred greater risk, with ORs (and 95% confidence intervals) of 2.8 (1.6-5.1) for one, 5.4 (2.7-10.6) for 2, and 27.3 (7.4-99.8) for 3 or 4 high-risk genotypes. In contrast, these polymorphisms were not consistently related to the risks of esophageal or gastric cardia cancers. Polymorphisms in IL-4 and IL-6 were not associated with any of the cancers studied. CONCLUSIONS: A proinflammatory cytokine genetic profile increases the risk of noncardia gastric adenocarcinoma but not other upper gastrointestinal cancers, possibly by inducing a hypochlorhydric and atrophic response to gastric H. pylori infection.     

Association of the human leukocyte antigen class II alleles with chronic atrophic gastritis and gastric carcinoma in Koreans

OBJECTIVE: Gastric carcinogenesis is a multi‐step process and is influenced by several etiological agents, including the host's genetic factors. Since whether a patient remains with chronic superficial gastritis (CSG) or progresses to either chronic atrophic gastritis (CAG) or gastric carcinoma (GC) could be a genetic predisposition unique in each population, we hypothesized that host human leukocyte antigen (HLA) alleles could be discriminative in predicting the risk of CSG progression to precancerous CAG and GC in Koreans. METHODS: A total of 165 patients with gastric disorders (CSG, 62; CAG, 69 and GC, 34), were selected to investigate the association of HLA class II alleles with the progression of CSG to CAG or GC. HLA genotypes were obtained by the polymerase chain reaction‐sequence based typing method. RESULTS: The phenotypic frequencies of DRB1*1101 and DQA1*0505 were significantly higher in the CAG group compared to those in the CSG group. In the subjects with Helicobacter pylori (H. pypori) (+), the frequencies of DRB1*1501 and DQB1*0602 were significantly lower in the CAG compared to those in the CSG. Further analysis showed that sex (P < 0.05, OR= 0.41–0.42) and age (P < 0.05, OR= 1.05) also affected the risk of progression from CSG to CAG in H. pylori (+) patients carrying the DRB1*1501 or DQB1*0602 allele. Additionally, the frequency of DRB1*0404 in the GC group was significantly higher than that in the gastritis group. CONCLUSION: Our findings strongly imply an association between HLA class II alleles and the risk of CAG development and GC progression in Koreans.     

A functional polymorphism of toll-like receptor 4 gene increases risk of gastric carcinoma and its precursors

BACKGROUND AND AIMS: TLR4 is a cell-surface signaling receptor involved in the recognition and host response to Helicobacter pylori. The TLR4+896A>G polymorphism linked with impaired reactivity to bacterial lipopolysaccharide may play a role in gastric carcinogenesis. METHODS: We assessed associations with premalignant gastric changes in 149 relatives of gastric cancer patients, including 45 with hypochlorhydria and gastric atrophy. We also genotyped 2 independent Caucasian population-based case-control studies of upper gastrointestinal tract cancer, initially in 312 noncardia gastric carcinoma cases and 419 controls and then in 184 noncardia gastric carcinomas, 123 cardia carcinomas, 159 esophageal cancers, and 211 frequency-matched controls. Odds ratios were computed from logistic models and adjusted for potential confounding factors. RESULTS: TLR4+896G carriers had an 11-fold (95% confidence interval [CI], 2.5-48) increased odds ratio (OR) for hypochlorhydria; the polymorphism was unassociated with gastric acid output in the absence of H pylori infection. Carriers also had significantly more severe gastric atrophy and inflammation. Seventeen percent of gastric carcinoma patients in the initial study and 15% of the noncardia gastric carcinoma patients in the replication study had 1 or 2 TLR4 variant alleles vs 8% of both control populations (combined OR = 2.3; 95% CI = 1.6-3.4). In contrast, prevalence of TLR4+896G was not significantly increased in esophageal squamous cell (2%, OR = 0.2) or adenocarcinoma (9%, OR = 1.4) or gastric cardia carcinoma (11%, OR = 1.4). CONCLUSIONS: Our data suggest that the TLR4+896A>G polymorphism is a risk factor for noncardia gastric carcinoma and its precursors. The findings underscore the role of the host innate immune response in outcome of H pylori infection.     

Helicobacter pylori, chronic atrophic gastritis, inactive aldehyde dehydrogenase-2, macrocytosis and multiple upper aerodigestive tract cancers and the risk for gastric cancer in alcoholic Japanese men

BACKGROUND: Gastric carcinoma occurs at a high rate in alcoholic Japanese men. Inactive heterozygous aldehyde dehydrogenase-2 (ALDH2*1/2*2) and macrocytosis (mean corpuscular volume [MCV] > or = 106 fl) enhance the risk for esophageal carcinoma, which frequently occurs with gastric carcinoma in this population. Whether alcoholism affects Helicobacter pylori-induced chronic atrophic gastritis (CAG) is unknown. METHODS: This study of Japanese alcoholic men with (n = 45) and without (n = 281) gastric carcinoma included assessment of H. pylori IgG antibody, serum pepsinogen-confirmed CAG, MCV, and ALDH2 genotype. RESULTS: The gastric carcinoma cases had a significantly higher age-adjusted prevalence of H. pylori-positivity (78%vs 57%), CAG (78%vs 42%), ALDH2*1/2*2 (36%vs 14%), MCV > or =106 fl (38%vs 20%), and concurrent esophageal/oropharyngolaryngeal carcinoma (18%vs 5%) than controls. Among gastric cancer-free controls, the prevalence of CAG was higher than generally reported in Japan, regardless of H. pylori status (H. pylori-positive, 56%vs 35-36% for Japanese general population; H. pylori-negative, 8%vs 1-3%). Alcoholism may accelerate the progression of CAG. Each of these factors increased the risk of gastric carcinoma (OR(s) = 3.7 for H. pylori-positive, 2.7 for non-severe CAG, 8.7 for severe CAG, 3.5 for ALDH2*1/2*2, 2.5 for MCV > or =106 fl, and 3.7 for concurrent carcinoma). A multivariate analysis showed that CAG and ALDH2*1/2*2 were independently related to the risk of gastric carcinoma. Combinations of CAG and ALDH2*1/2*2 showed greater risks of gastric carcinoma (OR(s) = 4.0 for non-severe CAG alone, 17.6 for severe CAG alone, 9.7 for ALDH2*1/2*2 alone, 17.1 for non-severe CAG plus ALDH2*1/2*2, and 39.2 for severe CAG plus ALDH2*1/2*2). CONCLUSIONS: Combining blood tests for H. pylori, CAG, MCV and ALDH2 genotype could offer a new means of predicting risk of gastric carcinoma in Japanese alcoholic men.     

IL1B and IL1RN polymorphic genes and Helicobacter pylori cagA strains decrease the risk of reflux esophagitis

BACKGROUND & AIMS: Proinflammatory interleukin (IL)-1 gene polymorphisms associated with high levels of IL-1beta activity increase the risk for hypochlorhydria and distal gastric carcinoma. The aim of this study was to evaluate whether carriers of these polymorphic genes are protected against gastroesophageal reflux disease (GERD). TNFA-308 polymorphisms were also studied. METHODS: We prospectively evaluated 385 patients without gastric cancer and peptic ulcer. Of these patients, 383 (98 with GERD and 285 controls) were successfully genotyped for all cytokines studied. The cagA status of Helicobacter pylori isolates was determined by polymerase chain reaction (PCR). IL1B-511/-31, IL1RN, and TNFA-308 polymorphisms were genotyped by PCR, PCR/restriction fragment length polymorphism, or PCR/confronting 2-pair primers. Histologic gastritis was assessed according to the updated Sydney system. The role of the proinflammatory cytokine genotypes in the genesis of GERD was evaluated before and after stratification by H. pylori status in logistic regression models controlling for confounding factors. RESULTS: IL1B-31 (a near-complete linkage disequilibrium between polymorphism at -31 and -511 was found) and IL1RN*2 allele polymorphisms were associated with GERD. After stratification, in the group of H. pylori-positive patients, cagA-positive status, IL1B-31 polymorphic alleles, IL1RN*2 alleles, and the degree of corpus gastritis were negatively associated with GERD. In the H. pylori-negative group, IL1B-31C/C genotype was inversely associated with GERD even after adjustment for age and sex. CONCLUSIONS: This study provides evidence supporting the independent protective role of cagA-positive H. pylori status and IL1B and ILRN allele polymorphisms against GERD.     

Systemic inflammation and COPD: the Framingham Heart Study

BACKGROUND: The current paradigm for the pathogenesis of COPD includes an ultimately maladaptive local inflammatory response to environmental stimuli. We examined the hypothesis that systemic inflammatory biomarkers are associated with impaired lung function, particularly among those with extensive cigarette smoking. METHODS: Using data from the Framingham Heart Study, we examined cross-sectional associations of systemic inflammatory biomarkers (CD40 ligand [CD40L], intercellular adhesion molecule [ICAM]-1, interleukin [IL]-6, monocyte chemoattractant protein-1, P-selectin, and myeloperoxidase, in addition to C-reactive protein) to impaired lung function. RESULTS: IL-6 was consistently associated with impaired lung function; a 1-SD higher concentration of IL-6 was associated with a 41-mL lower FEV(1) (95% confidence interval [CI], - 61 to - 20) and a borderline 15% higher odds of COPD (odds ratio, 1.15; 95% CI, 0.99 to 1.34). Additionally, P-selectin was associated with lower FEV(1) levels; after adjusting for the other biomarkers, a 1-SD higher concentration of P-selectin predicted an FEV(1) that was on average 19 mL lower (95% CI, - 37 to 0). Including the biomarkers individually as sole exposures in the models generally strengthened the impaired lung function/biomarker association; the relations of ICAM-1 to FEV(1), and ICAM and CD40L to COPD became significant. The observed associations did not vary significantly with smoking history, except that the association between CD40L and COPD appeared greater in individuals with more extensive smoking histories. CONCLUSIONS: Among participants in the Framingham Heart Study, systemic inflammation was associated with lower levels of pulmonary function. Further research into the role of systemic inflammation in the development of pulmonary dysfunction is merited.