Re: helicobacter pylori infection and gastric cancer: facing the enigmas

Helicobacter pylori infection and gastropathy: A comparison between Indonesian and Japanese patients

AIM: To compare the effects of Helicobacter pylori (H pylori) infection on gastropathy between Indonesian and Japanese patients.

METHODS: Biopsy specimens were obtained during upper gastrointestinal endoscopy from 167 subjects (125 Indonesians and 42 Japanese) with uninvestigated symptoms of dyspepsia. The specimens were analyzed for the presence of H pylori using urease analysis, histopathology, and cell culture. The grade and activity of gastritis was assessed using the updated Sydney system.

RESULTS: The percentages of Indonesian and Japanese patients who were H pylori-positive at the antrum or body of the stomach were similar (68% and 59.5%, respectively; P = 0.316). Of those who were H pylori-positive, more Japanese patients than Indonesian patients had high levels of polymorphonuclear cells (P = 0.001), mononuclear cells (P = 0.013), glandular atrophy (P = 0.000), and intestinal metaplasia (P = 0.011) in both the antrum and body of the stomach.

CONCLUSION: The grade of gastritis and prevalence of mucosal atrophy and intestinal metaplasia were higher in Japanese patients. The difference between Indonesian and Japanese patients was significant.

Prevalence of Helicobacter pylori infection, chronic gastritis, and intestinal metaplasia in Mozambican dyspeptic patients

We estimated the prevalence of Helicobacter pylori infection, chronic gastritis, atrophy, and intestinal metaplasia in dyspeptic patients from Maputo Central Hospital, Mozambique and evaluated the relationship between infection and histopathological features of chronic gastritis. Biopsies from 109 consecutive patients observed in 2005-2006 were collected from antrum, incisura angularis, and corpus for histopathological study according to the Modified Sydney system. H. pylori infection was assessed by histology and polymerase chain reaction. H. pylori prevalence was 94.5%. Chronic gastritis was the most frequent diagnosis (90.8%). Degenerative surface epithelial damage was associated with higher H. pylori density. Glandular atrophy (8.3%) and intestinal metaplasia (8.3%) were infrequent. Our results confirm previous observations in African countries with high prevalence of H. pylori infection and low rates of gastric cancer: high frequency of chronic H. pylori-associated gastritis with very low frequency of gastric atrophy and intestinal metaplasia.

Gastric cancer is related to early Helicobacter pylori infection in a high-prevalence country

BACKGROUND AND AIMS

Chile ranks fifth in the world among countries with the highest incidence of gastric cancer. The aim was to quantify the association between Helicobacter pylori infection and gastric cancer mortality at the county of residence.

METHODS

A cross-sectional household survey, a probability sample of the Chilean adult population, provided 2,615 participants in whom serum H. pylori IgG antibodies were measured (ELISA). The spatial pattern of 48,367 deaths due to gastric cancer which occurred from 1985 to 2002 was analyzed using a hierarchical Poisson regression model; 333 counties were categorized as low, medium, and high gastric cancer mortality with median gastric cancer death rates of 11.4, 19.1, and 26.0 per 100,000 inhabitants, respectively. The association between H. pylori positivity and gastric cancer mortality in the county of residence was assessed by multivariate Poisson regression for complex samples.

RESULTS

H. pylori prevalence was 73.0% [95% confidence intervals (CI), 70.0-76.0], higher in men [prevalence rate ratio (PRR), 1.1 (95% CI, 1.01-1.20)], peaked at ages 45 to 64, and dropped after age 65. It was higher among residents in counties with high gastric cancer mortality (79.7%; 95% CI, 76.4-82.6) compared to counties with low gastric cancer mortality (62.3%; 95% CI, 53.8-70.2; corresponding PRR, 1.3; 95% CI, 1.1-1.5); under age 24, H. pylori infection was 79.7% (95% CI, 72.2-85.6) versus 39.8% (95% CI, 19.6-64.2) among residents in counties with high and low gastric cancer mortalities, respectively (PRR, 2.0; 95% CI, 1.1-3.7).

CONCLUSIONS

The high prevalence of H. pylori at younger ages was associated with high gastric cancer mortality in the base population.

Dietary modulation of the multistage, multimechanisms of human carcinogenesis: effects on initiated stem cells and cell-cell communication

Diet can influence the risk to cancer in both negative and positive ways. Worldwide, more than 10 million persons develop cancer annually. Diet could prevent many cancers. Carcinogenesis is a multistage, multimechanism process, consisting of "initiation," "promotion," and "progression" phases. Although diet could affect each phase, an efficacious strategy for dietary chemoprevention would be intervention during the promotion phase. The tumor-promotion process requires sustained exposure to agents that stimulate the growth and inhibition of apoptosis of initiated cells in the absence of antipromoters. Chronic inflammation has been associated with the promotion process. The mechanism affecting the promotion process appears to be the inhibition of cell-cell communication between normal and initiated cells. Most, if not all, tumor-promoting agents and conditions, reversibly, inhibit cell-cell communication, whereas antipromoters, antioxidants, and anti-inflammatory agents have been shown to ameliorate the effects of tumor promoters on cell-cell communication. Additionally, adult stem cells are hypothesized to be the target cells for initiating the carcinogenic process. A new paradigm has been presented that postulates the first function of the carcinogenic process is to block the "mortalization" of a normal, "immortal" adult stem cell rather than the induction of "immortalization" of a normal mortal cell.