Association of Helicobacter pylori with carcinoma of stomach.

OBJECTIVE To note the association of Helicobacter pylori in patients having carcinoma of stomach. METHODS A descriptive study was carried out at the Department of Histopathology, Ziauddin Medical University, Karachi from April 1992 to May 1998. Histological evaluation of 50 cases of carcinoma of stomach was compared with 50 cases each of chronic gastritis and histological normal gastric mucosa. Only those cases of carcinoma of stomach were included that contained sufficient non-neoplastic mucosa in addition to tumour tissue. Three glass slides with serial sections of each case of carcinoma of stomach, chronic gastritis and normal gastric mucosa were freshly cut and stained with H&E, PAS and Giemsa stains. All slides were examined by light microscopy. RESULTS Helicobacter pylori were identified in 35 cases (70%) of carcinoma of stomach, in 42 cases (84%) of chronic gastritis, and in 12 cases (24%) of normal gastric mucosa. The presence of H. pylori in cases of carcinoma of stomach and chronic gastritis was highly significant (P < 0.001) as compared to normal gastric mucosa. Chronic gastritis was observed in the non-neoplastic mucosa in 48 cases (96%) with carcinoma of stomach. Of 50 cases with carcinoma of the stomach, intestinal type of carcinoma was found in 30 cases (70%), and diffuse type in 15 cases (30%). No significant difference was noted in the prevalence of H. pylori between intestinal type (69%) and diffuse type (71%) gastric carcinoma. Significant Helicobacter pylori associated chronic gastritis was observed in intestinal type (94%) and diffuse type (100%) of gastric carcinoma. The prevalence of H. pylori was insignificant in the presence or absence of mucosal atrophy and intestinal metaplasia in both types of gastric carcinoma. CONCLUSION A significant number of H. pylori were found in patients of carcinoma of stomach. Both intestinal and diffuse types of gastric carcinoma showed strong association with H. pylori. Chronic gastritis appears to be the background lesion while atrophy and intestinal metaplasia indicate long term infection.