Helicobacter pylori infection and atrophic gastritis. A case-control study in a rural town of Japan

Clinical Benefit and Cost Effectiveness of Risk-Stratified Gastric Cancer Screening Strategies in China: A Modeling Study

BACKGROUND AND OBJECTIVE

A new gastric cancer screening scoring system (NGCS) strategy was recommended for the early gastric cancer (GC) screening process in China. The current study aimed to assess the clinical benefits and the cost effectiveness of the NGCS strategy in GC high-risk areas of China from a societal perspective.

METHODS

A Markov microsimulation model was developed to evaluate 30 alternative screening strategies with varying initiation age, including the NGCS strategy, the modified NGCS strategy, and the endoscopic screening strategy with various screening intervals. The primary outcomes included GC mortality, number of endoscopies, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Cost estimates were reported in 2021 USD (US$) and both costs and benefits were discounted at 5% annually. Deterministic and probabilistic sensitivity analyses were performed to evaluate model uncertainty.

RESULTS

Screening with the NGCS strategy from age 40 years (40-NGCS) reduced the GC incidence by 86.4%, which provided the greatest benefit across strategies. Compared with all strategies, at a willingness-to pay threshold of US$17,922 per QALY, the 40-NGCS strategy was a leading cost-effective strategy, with an ICER of US$15,668 per QALY. Results were robust in univariate and probabilistic sensitivity analyses. The probability of the 40-NGCS strategy being cost effective was 0.863.

CONCLUSIONS

The 40-NGCS strategy was an effective and cost-effective strategy to reduce GC incidence and mortality in China. The findings provide important evidence for decision makers to formulate and optimize targeted approaches for GC prevention and control policies in China.

Gastric adenocarcinoma screening and prevention in the era of new biomarker and endoscopic technologies: a cost-effectiveness analysis

OBJECTIVE

To estimate the cost-effectiveness of noncardia gastric adenocarcinoma (NCGA) screening strategies based on new biomarker and endoscopic technologies.

DESIGN

Using an intestinal-type NCGA microsimulation model, we evaluated the following one-time screening strategies for US men: (1) serum pepsinogen to detect gastric atrophy (with endoscopic follow-up of positive screen results), (2) endoscopic screening to detect dysplasia and asymptomatic cancer (with endoscopic mucosal resection (EMR) treatment for detected lesions) and (3) Helicobacter pylori screening and treatment. Screening performance, treatment effectiveness, cancer and cost data were based on published literature and databases. Subgroups included current, former and never smokers. Outcomes included lifetime cancer risk and incremental cost-effectiveness ratios (ICERs), expressed as cost per quality-adjusted-life-year (QALY) gained.

RESULTS

Screening the general population at age 50 years reduced the lifetime intestinal-type NCGA risk (0.24%) by 26.4% with serum pepsinogen screening, 21.2% with endoscopy and EMR and 0.2% with H. pylori screening/treatment. Targeting current smokers reduced the lifetime risk (0.35%) by 30.8%, 25.5%, and 0.1%, respectively. For all subgroups, serum pepsinogen screening was more effective and more cost-effective than all other strategies, although its ICER varied from $76,000/QALY (current smokers) to $105,400/QALY (general population). Results were sensitive to H. pylori prevalence, screen age and serum pepsinogen test sensitivity. Probabilistic sensitivity analysis found that at a $100,000/QALY willingness-to-pay threshold, the probability that serum pepsinogen screening was preferred was 0.97 for current smokers.

CONCLUSIONS

Although not warranted for the general population, targeting high-risk smokers for serum pepsinogen screening may be a cost-effective strategy to reduce intestinal-type NCGA mortality.

Serologically Determined Gastric Mucosal Condition Is a Predictive Factor for Osteoporosis in Japanese Men

BACKGROUND

There are few reports about the influence of Helicobacter pylori infection and/or atrophic gastritis on bone conditions in Japan.

AIMS

To assess whether the combination of serologically determined Helicobacter pylori infection and atrophic gastritis is available as a biomarker for bone conditions.

METHODS

We studied 230 men in their 50s and 60s. Helicobacter pylori infection was determined using serum antibody to this bacterium. Atrophic gastritis was diagnosed on the basis of the serum pepsinogen I and II criteria. The characteristics of the participants' bone were measured at the radius using an ultrasonic bone densitometry system. The risks of low trabecular bone density, low elastic modulus of trabecular bone, and low cortical thickness among subjects who were positive for Helicobacter pylori infection and/or atrophic gastritis relative to those who were not were calculated.

RESULTS

Helicobacter pylori infection significantly increased the risk of low trabecular bone density (odds ratio 1.83, 95 % confidence interval 1.04-3.21, P = 0.03). Atrophic gastritis significantly increased the risk of low trabecular bone density (2.22, 1.17-4.22, 0.01). Compared with anti-Helicobacter pylori antibody (-) and atrophic gastritis (-) subjects, anti-Helicobacter pylori antibody (+) and atrophic gastritis (+) subjects were a significant high-risk group for low trabecular bone density (2.65, 1.27-5.55, 0.01).

CONCLUSIONS

A serological diagnosis of Helicobacter pylori infection and atrophic gastritis, which is utilized for risk assessment of gastric cancer, was suggested to be useful for risk assessment of osteoporosis.

Geographic diversity of Helicobacter pylori in cadavers: forensic estimation of geographical origin

A method for determining the geographical origin of unidentified cadavers by determining the genotype of Helicobacter pylori, which is latent in one-half of the world's population, was developed. In the first stage, DNA was extracted from samplings at 5 points in the gastric mucosa of 177 individuals randomly selected from cadavers undergoing medico-legal autopsy. 16S-rDNA of H. pylori DNA was detected by polymerase chain reaction (PCR) in 101 cadavers (57.0%); by sex, 74 of 123 (60.1%) males and 28 of 54 (46.4%) females were positive. There were no significant differences in H. pylori detection rate among the 5 sampling points of the gastric mucosa, cause of death, or age. In the second stage, amplified fragments of H. pylori vacA regions s and m from 17 individuals with the following ethnic backgrounds were sequenced: Japanese, 10; Chinese, 2; South Korean, 1; Taiwanese, 1; Thai, 1; Afghan, 1; and Filipino, 1. A phylogenetic tree constructed with these and 28 previously reported H. pylori strain sequences revealed 3 major gene clusters consisting of East Asian type I (Japanese, South Korean and Chinese), Western type II, and Southeast Asia type III. The Taiwanese and Filipino samples deviated from the clusters type III to which they typically belong. The ultimate aim of the present study was to develop a more accurate method of determining of geographic origin of unidentified cadavers through the combination of the present method with other, virus-based methods H. pylori DNA was detected from over half of the cadavers tested and vacA genotypes showed specificity to geographical origin. Therefore, these results suggest that the H. pylori genome provides valuable additional information for tracing the geographical origin of unidentified cadavers.

Epidemiologic findings on serologically defined chronic atrophic gastritis strongly depend on the choice of the cutoff-value

Chronic atrophic gastritis (CAG), a precursor of intestinal gastric cancer, is mostly ascertained noninvasively by serum pepsinogens in epidemiologic studies. However, serological definitions vary widely. We aimed to investigate the impact of this variation on estimated prevalence of CAG and its association with its main risk factors, age and Helicobacter pylori infection. Serum pepsinogen I and II and antibodies against H. pylori were measured by ELISA among 9,444 women and men aged 50-74 years in a population-based cohort study in Saarland/Germany. Application of the various definitions resulted in a wide range of prevalence estimates of CAG prevalence (2.1%-8.2%, with an outlier of 18.8% for one particular definition) and its associations with age and H. pylori infection (age adjusted odds ratios, OR, for CagA positive H. pylori infection: 0.98-4.48). Definitions of CAG based on both pepsinogen I and the pepsinogen I/II ratio or on the pepsinogen I/II ratio only revealed much clearer associations with both age and H. pylori infection than definitions of CAG based on pepsinogen I only (ORs for H. pylori infection: 1.45-4.48 and 0.86-1.30, respectively). Epidemiologic findings on CAG lack comparability due to the heterogeneity in serologic definitions of CAG. The association of age and H. pylori infection with CAG may be strongly underestimated in studies in which CAG is defined by pepsinogen I only.

Erosive esophagitis in the Philippines: a comparison between two time periods

BACKGROUND

In Asia, the incidence of gastroesophageal reflux disease diagnosed through endoscopy has increased from 3-9% to 14-16% in the last decade. The aim of this study was to determine the prevalence of erosive esophagitis (EE) over a span of 10 years in a tertiary care facility in the Philippines.

METHODS

All patients diagnosed with EE from 1994 to 1997 (period A) and from 2000 to 2003 (period B) were included in the study. The modified Savary-Miller and Los Angeles classifications were used to grade EE for periods A and B, respectively.

RESULTS

A total of 15 981 upper endoscopies were evaluated for this study. There was no significant difference in the male: female ratio (period A 1.43:1 vs period B 1.25:1, P = 0.459) and in the mean age of patients with EE (period A 46.4 vs period B 47.5, P = 0.395). The prevalence of EE was significantly higher (P < 0.0001) in period B (6.3%) as compared to period A (2.9%). However, despite a higher prevalence, more patients had mild esophagitis in period B as compared to period A. Conversely, there were more patients with esophageal ulcers (18.6%vs 5.9%, P < 0.001), esophageal strictures (2.3%vs 0%, P = 0.003), and hiatal hernia (15.8%vs 7.5%, P = 0.001) in period A. The presence of concomitant Barrett's esophagus was not significantly different between the two time periods (period A 3.2%vs period B 5%, P = 0.367).

CONCLUSIONS

The prevalence of EE was higher in 2000-2003 than in 1994-1997, although the complications associated with the disease diminished. The prevalence of concomitant Barrett's esophagus remained stable.

Epidemiology of chronic atrophic gastritis: population-based study among 9444 older adults from Germany

BACKGROUND

Epidemiological data on chronic atrophic gastritis from general population samples are sparse in Germany.

AIM

To assess prevalence of chronic atrophic gastritis according to potential risk factors and clinical outcomes in a large-scale population-based study.

METHODS

In the baseline examination of ESTHER, a population-based cohort study conducted in Germany, serological measurements of pepsinogen (PG) I and II and Helicobacter pylori antibodies were taken in 9444 women and men aged 50-74 years. Information on potential risk factors and medical history were obtained by questionnaire.

RESULTS

With the definition used in the EUROGAST study (PG I < 25 ng/mL), prevalence of chronic atrophic gastritis increased from 4.8% in age group 50-54 to 8.7% in age group 70-74. An alternative definition of chronic atrophic gastritis (PG I < 70 ng/mL and PG I/PG II < 3), used in multiple studies from Japan, revealed a greater increase with age (from 2.7% to 9.1%) and a strong association with H. pylori infection (adjusted odds ratio: 2.9, 95% confidence interval: 2.4-3.7). With both definitions, a strong inverse association with heartburn was observed.

CONCLUSIONS

Overall chronic atrophic gastritis prevalence is low among older adults in Germany, but it strongly increases with age and H. pylori infection.

Reduction in gastric cancer mortality by screening based on serum pepsinogen concentration: a case-control study

OBJECTIVE

Pepsinogen testing is widely used in Japan as a method of screening for gastric cancer. To evaluate the efficacy of this method, a case-control study was conducted in a rural town in Hiroshima prefecture, Japan, where no previous pepsinogen testing had been performed.

MATERIAL AND METHODS

Three age-and gender-matched control subjects were randomly selected for each of 41 individuals who had died of gastric cancer. The three control subjects were selected from individuals who were living in the same area as the patient when gastric cancer was diagnosed.

RESULTS

The odds ratios for death from gastric cancer among control subjects screened within 1 and 2 years before the individuals were diagnosed versus those not screened were 0.238 (95% confidence interval (CI): 0.061-0.929), and 0.375 (95% CI: 0.155-0.905), respectively.

CONCLUSIONS

The study results suggest that gastric cancer screening using the pepsinogen method may reduce mortality from gastric cancer.

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.

Prevalence of chronic atrophic gastritis in different parts of the world

Chronic atrophic gastritis (CAG) is a well-established precursor of intestinal gastric cancer, but epidemiologic data about its occurrence are sparse. We provide an overview on studies that examined the prevalence of CAG in different parts of the world. Articles containing data about the prevalence of chronic atrophic gastritis in unselected population samples and published until November 2005 were identified by searching the MEDLINE database. Furthermore, the references in the identified publications were screened for additional suitable studies. Studies comprising at least 50 subjects were included. Forty-one studies providing data on the prevalence of CAG in unselected population samples could be identified. CAG was determined by gastroscopy in 15 studies and by pepsinogen serum levels in 26 studies. Although results are difficult to compare due to the various definitions of CAG used, a strong increase with age, the lack of major gender differences, and strong variations between populations and population groups (in particular, relatively high rates in certain Asian populations) could be observed quite consistently. We conclude that CAG is relatively common among older adults in different parts of the world, but large variations exist. Large-scale international comparative studies with standardized methodology to determine CAG are needed to provide a coherent picture of the epidemiology of CAG in various populations. Noninvasive measurements of CAG by pepsinogen levels may be particularly suited for that purpose.

Progression of chronic atrophic gastritis associated with Helicobacter pylori infection increases risk of gastric cancer

We conducted a longitudinal cohort study to determine the association of Helicobacter pylori infection and the progression of chronic atrophic gastritis (CAG) with gastric cancer. A cohort of 4655 healthy asymptomatic subjects was followed for a mean period of 7.7 years. H. pylori infection was established by serum specific antibodies and the presence of CAG was confirmed by serum pepsinogen. During the follow-up period, 45 gastric cancer cases were detected (incidence rate, 126/100000 person-years). A univariate analysis after adjustment for age showed that both H. pylori and CAG were significantly associated with gastric cancer. To clarify the interaction between H. pylori and CAG, an analysis stratified by H. pylori- and CAG-status was performed. No cancer developed in the H. pylori(-)/CAG(-) group during the study period. This supports the theory that it is quite rare for any type of gastric cancer to develop in an H. pylori-free healthy stomach. With the progression of H. pylori-induced gastritis, the risk of gastric cancer increased in a stepwise fashion from CAG-free gastritis [H. pylori(+)/CAG(-) group] (HR=7.13, 95%CI=0.95-53.33) to CAG [H. pylori(+)/CAG(+) group] (HR=14.85, 95%CI=1.96-107.7) and finally to severe CAG with extensive intestinal metaplasia [H. pylori(-)/CAG(+) group] (HR=61.85, 95%CI=5.6-682.64) in which loss of H. pylori from the stomach is observed. Therefore, it is probable that H. pylori alone is not directly associated with stomach carcinogenesis. Instead, H. pylori appears to influence stomach carcinogenesis through the development of CAG. The observed positive correlation between the extent of H. pylori-induced gastritis and the development of cancer was strong, especially for the intestinal type. These results are compelling evidence that severe gastritis with extensive intestinal metaplasia is a major risk factor for gastric cancer, and they confirm the previously described model of stomach carcinogenesis: the gastritis-metaplasia-carcinoma sequence.

Cobalamin, folate, methylmalonic acid, homocysteine, and gastritis markers in dementia

The prevalence of dementia disorders, cobalamin and/or folate deficiency as well as gastritis increases with age. To investigate whether there is an association between these conditions, plasma homocysteine (Hcy), serum methylmalonic acid, serum cobalamin and blood folate concentrations were measured. Gastritis was indirectly diagnosed by measuring serum antibodies against H,K-ATPase, HELICOBACTER PYLORI and intrinsic factor, using enzyme-linked immunosorbent assays. The studied groups consisted of 47 patients with Alzheimer's disease (AD), 9 with AD pathology in combination with additive vascular lesions, 59 with vascular dementia, 8 who were cognitively impaired, and 101 control cases. Plasma Hcy concentrations were significantly elevated in the dementia groups, with the highest levels in patients with vascular pathology. We conclude that hyperhomocysteinemia is a common finding in patients with dementia disorders of different etiologies. The markers for gastritis did not contribute to an elucidation of a possible connection between this condition, dementia disorders, or cobalamin/folate deficiency.

Food/nutrient intake and risk of atrophic gastritis among the Helicobacter pylori-infected population of northeastern Japan

Although Helicobacter pylori (H. pylori ) infection is considered a key risk factor for atrophic gastritis, along with other environmental factors, it is still unclear which factor is involved in the development of atrophic gastritis among H. pylori-infected subjects. In the present cross-sectional study, therefore, we analyzed various dietary factors in relation to the presence of atrophic gastritis among H. pylori-infected subjects who participated in a health check-up program in a town in northeastern Japan. One thousand and seventy-one subjects (362 males and 709 females) who provided both self-administered validated food frequency questionnaires and blood samples were the basis for the study, and all of them were serologically positive for H. pylori immunoglobulin G (IgG) antibody. Among them, 663 (223 males and 440 females) were diagnosed as having atrophic gastritis on the basis of serum pepsinogen levels. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated based on tertile categories of subjects without atrophic gastritis, using logistic regression analysis. Among females, high consumptions of rice (OR = 1.6, 95% CI: 1.1-2.3), cod roe (OR = 1.5, 95% CI: 1.0-2.2) and cuttlefish (OR = 1.5, 95% CI: 1.0-2.3) were associated with a moderately increased risk of atrophic gastritis after adjustment for age (P for trend = 0.02 for these items). Among males, high consumptions of rice and miso soup showed a tendency toward an increased risk (P for trend = 0.12 and 0.13, respectively). Vegetables and fruits showed no association among either males or females. From these results, it is suggested that the dietary habits of consumers of traditional Japanese foods may play a role in the development of atrophic gastritis after H. pylori infection.

Association of Helicobacter pylori infection with atrophic gastritis and intestinal metaplasia

AIMS

To evaluate the effect of Helicobacter pylori infection and aging on atrophy and intestinal metaplasia of the gastric mucosa.

METHODS

One hundred and sixty-three patients were divided into three age groups and underwent an upper gastrointestinal endoscopy where no esophagitis, peptic ulcers, or malignancies were detected. Two biopsy specimens were obtained from the anterior and posterior walls of the antrum and of the fundus. These were used to evaluate the grade of gastritis, bacterial culture and histologic evidence of H. pylori infection.

RESULTS

Helicobacter pylori infection was found to be directly associated with an increased risk of gastritis grade (odds ratio (OR) = 90 (95% CI; 30-270)). An age of 60 years and older along with H. pylori infection was also strongly associated with an increased risk of atrophy (OR = 6.6, (95% CI; 2.9-15.2)); OR = 9.8, (95% CI; 2.7-35.4)), as was intestinal metaplasia of the gastric mucosa (OR = 5.5, (95% CI; 1.7-17.6)); OR = 7.9, (95% CI; 2.8-46.1)). The prevalence of atrophic gastritis increased with advancing age in H. pylori-infected patients, but no such phenomenon was observed in H. pylori-uninfected patients. The prevalence of intestinal metaplasia significantly increased with advancing age, irrespective of the presence of H. pylori infection. In addition, H. pylori uninfected female patients had a decreased risk of intestinal metaplasia.

CONCLUSIONS

These results suggest that atrophic gastritis is not a normal aging process, but instead is likely to be the result of H. pylori infection, while intestinal metaplasia is caused by both the aging process and H. pylori infection. A decreased risk of intestinal metaplasia found in uninfected female subjects may partly explain the lower prevalence of gastric cancer in females than in males.

Gastro-oesophageal reflux disease in Asia

Gastro-oesophageal reflux disease (GORD) occurs more frequently in Europe and North America than in Asia but its prevalence is now increasing in many Asian countries. Many reasons have been given for the lower prevalence of GORD in Asia. Low dietary fat and genetically determined factors, such as body mass index and maximal acid output, may be important. Other dietary factors appear to be less relevant. Increased intake of carbonated drinks or aggravating medicines may influence the increasing rates of GORD in some Asian countries but no strong evidence links other factors, such as the age of the population, smoking or alcohol consumption, to GORD. The management of GORD in Asia is similar to that in Europe and North America but the lower incidence of severe oesophagitis in Asia may alter the approach slightly. Also, because Asians tend to develop stomach cancer at an earlier age, endoscopy is used routinely at an earlier stage of investigation. Gastro-oesophageal reflux disease is essentially a motility disorder, so short-term management of the disease can usually be achieved using prokinetic agents (or histamine (H2)-receptor antagonists). More severe and recurrent GORD may require proton pump inhibitors (PPI) or a combination of prokinetic agents and PPI. The choice of long-term treatment may be influenced by the relative costs of prokinetic agents and PPI.