Helicobacter pylori and primary gastric lymphoma

Abstract

Few previous articles have analyzed the relation between infection with Helicobacter pylori (H. pylori) and primary gastric lymphoma in a large number of patients. Resected and biopsied specimens from 237 patients with primary gastric lymphoma were investigated for H. pylori using hematoxylin and eosin stain, modified Giemsa stain, and immunohistochemistry. These specimens were compared with specimens from 29 patients with chronic active gastritis, 33 with peptic ulcers, and 41 with gastric carcinoma. H. pylori was detected in 145 of 237 patients (61%) with gastric lymphoma. The frequency of H. pylori positivity was higher in patients with lymphoma restricted to the mucosa and submucosa (76%) than in those with lymphoma invading beyond the submucosa (48%) (P < 0.001), and was also higher in patients with low grade mucosa-associated lymphoid tissue lymphoma (72%) than in those with high grade tumors (55%) (P < 0.05). The frequency of H. pylori positivity in patients with lymphoma was lower than in those with chronic active gastritis (100%) (P < 0.001) or peptic ulcer (91%) (P < 0.05). In patients with lymphoma restricted to the mucosa and the superficial portion of the submucosa, the frequency of H. pylori positivity (90%) was as high as that observed in patients with chronic active gastritis and peptic ulcer. The H. pylori grading score for patients with lymphoma (0.9 +/- 1.0) was lower than for those with chronic active gastritis (1.9 +/- 0.8) (P < 0.001), peptic ulcers (2.2 +/- 1.0) (P < 0.001), or gastric carcinoma (1.2 +/- 1.1) (P < 0.05). These results suggest that H. pylori is more likely to be associated with early states of primary gastric lymphoma than with advanced states. Thus, H. pylori may disappear during the progression of primary gastric lymphoma.