Gastric cancer in San Marinese and their first degree relatives in San Marino and the United States. Gastroscopic biopsy as an epidemiological tool

Review article: would eradication of Helicobacter pylori infection reduce the risk of gastric cancer?

This article reviews the data on the epidemiology of gastric cancer, to determine if treatment of an asymptomatic individual can be justified. It reviews retrospective and prospective case-control studies of gastric cancer in Italy and other countries. Mucosa-associated lymphoid tissue lymphoma is associated with Helicobacter pylori infection. The risk of noncardia gastric cancer is higher (4-fold or greater) in those with H. pylori infection. Although no studies have shown prevention following treatment, eradication of asymptomatic H. pylori infection in an individual in the age group 40 or lower may be expected to reduce the risk of gastric cancer.

Frequency of TPR-MET rearrangement in patients with gastric carcinoma and in first-degree relatives

BACKGROUND

The activation of the c-met protooncogene through a rearrangement has been detected previously in gastric carcinoma tissue and precancerous lesions. In the current study the authors analyzed the rearrangement of TPR-MET in gastric carcinoma patients and in first-degree relatives to evaluate the potential role and timepoint of this genetic alteration in the process of gastric carcinogenesis and its potential value in identifying those individuals with an increased risk of developing gastric carcinoma.

METHODS

The presence of TPR-MET mRNA was determined in gastric tissue from 19 patients with gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma and in the gastric mucosa of 18 first-degree relatives without gastric carcinoma using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. A 205-base pair (bp) cDNA fragment and a 70-bp cDNA fragment spanning the breakpoint were amplified by nested PCR. Amplification products were hybridized with an oligonucleotide labeled at the 3'-end with DIG-11-dUTP spanning the breakpoint using Southern blot analysis. The MNNG-HOS cell line served as a positive control.

RESULTS

TPR-MET mRNA was detected in nine gastric carcinoma patients (47%). Among these patients, TPR-MET mRNA was present in the both tumor and tumor free tissues in 5 patients (26%), in the tumor tissue only in 2 patients (11%), and in the tumor free gastric mucosa only in 2 patients (11%). It is interesting to note that TPR-MET rearrangement also was detected in the gastric corpus mucosa of 1 first-degree relative (6%), but in none of the control subjects.

CONCLUSIONS

The data from the current study indicate that TPR-MET activation may be an early event in gastric carcinogenesis and may be useful for the identification of individuals with an increased risk of developing gastric carcinoma.

A population based study of Helicobacter pylori infection in a European country: the San Marino Study. Relations with gastrointestinal diseases

Helicobacter pylori is present worldwide but few large population studies exist on the epidemiology of the infection. A random cross sectional study was performed of H pylori infection in the adult population of San Marino, a European country with high gastric cancer rate, to assess its prevalence and to evaluate its relations with gastrointestinal disease. In 2237 subjects (77% of the initial sample) H pylori IgG antibodies were detected with enzyme linked immunosorbent assay (ELISA) and immunoblotting. A questionnaire including questions about occupation, place of birth, and smoking was given to all subjects. Dyspepsia, peptic ulcer, and gastric cancer in the subjects, relatives, and partners as well as use of drug, dental treatment/prostheses, and gastrointestinal endoscopies, were evaluated by multivariate analysis. H pylori prevalence was of 51%, increased with age from 23% (20-29 years) to 68% (> or = 70 years), and was higher among manual workers. H pylori was independently associated with ulcer (OR = 1.63, 95% confidence intervals (CI) = 1.16 to 2.27), H2 antagonists (OR = 1.94, 95% CI = 1.21 to 3.10), and benzodiazepines (OR = 1.57, 95% CI = 1.02 to 2.42), dental prostheses (OR = 1.25, 95% CI = 1.05 to 1.49), gastroscopy in the past five years (OR = 1.50, 95% CI = 1.05 to 2.14), peptic ulcer in siblings (OR = 1.52, 95% CI = 1.09 to 2.12), gastric cancer in father (OR = 1.61, 95% CI = 1.02 to 2.52). The association of seropositivity with history of ulcer, gastric cancer in family, gastroscopy, and H2 antagonists suggests that H pylori is an epidemiological key factor in the pathogenesis of gastroduodenal diseases in this area.