[Helicobacter pylori in peptic ulcer and gastric cancer]

Recently many reports have shown a strong association between Helicobacter pylori infection in the stomach and recurrent peptic ulcer. Moreover, prospective cohort serological studies showed that H. pylori infected individuals have significantly increased rate of gastric cancer in the USA. H. pylori is a gram-negative spiral organism which has urease activity and produces ammonia and CO2 from urea, and nestles in the gastric pits and overlaying mucus gel layer. Many diagnostic methods of H. pylori infection are available; ie bacterial culture, 13C-urea breath test, histology, serum IgG antibody against H. pylori. We developed a new method, ie tissue IgA antibody against H. pylori and detection of H. pylori DNA in the gastric juice by PCR method. Triple therapies with metronidazole, bismuth compounds, and amoxicillin or tetracyclin are difficult to use in Japan because of their sever side effects. Thus, new methods with proton pump inhibitor (PPI) and amoxicillin have been introduced. We treated 14 patients of whom were H. pylori positive-active peptic ulcer with 30 mg/day of lansoprazole, a new PPI, plus 1,500 mg/day of amoxicillin for 2 weeks and 8 (57%) patients were eradicated. Gastric carcinogenesis are multi-steps and multifactorials process. Hypothetical sequence of intestinal type of gastric cancer is that superficial gastritis-->atrophic gastritis-->intestinal metaplasia-->dysplasia-->gastric cancer and H. pylori infection may play a role in the early stage of the sequence. We examined mucosal IgA antibody against H. pylori in chronic gastritis and intestinal metaplasia detected by the Tes-Tape method in 25 resected specimens after gastrectomy for gastric cancer. Positivity rates of tissue H. pylori IgA antibody were lower in the mucosa of intestinal metaplasia than in non-metaplastic gastric mucosa and were negative in carcinoma. Causal relationship between H. pylori infection and gastric cancer is not proven and factors other than H. pylori infection are also important in the gastric carcinogenesis. Finally we introduce 2 reports: (1) NIH Consensus Conference: Helicobacter pylori in peptic ulcer disease (JAMA. 1994; 272: 65-69). The consensus panel concluded that 1. ulcer patients with H. pylori infection require treatment with antimicrobial agents in addition to antisecretory drugs whether on first presentation with the illness or on recurrence; 2. the value of treating nonulcerative dyspepsia patients with H. pylori infection remains to be determined; and 3. the interesting relationship between H. pylori infection and gastric cancer requires further exploration. (2) World Health Organization: Working Group Meeting (Reported in World Congress of Gastroenterology, Los Angeles, 1994). H. pylori plays a causal role in the chain of events leading to cancer of the stomach. Group I: definite carcinogen.