A clinicopathologic study of gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND. It is still unclear which patients with gastric mucosa-associat ed lymphoid tissue (MALT) lymphoma will benefit from the eradication of Hel icobacter pylori. METHODS. The authors studied a total of 34 patients. Twenty-three patients had primary gastric lymphoma and underwent gastric resection as initial tre atment. Eleven patients with gastric MALT lymphoma who received antibiotics against H. pylori as initial treatment were also included. In all 34 patie nts, the presence of H. Pylori, endoscopic Endings, and pathologic features were evaluated. Immunohistochemical expression of Bcl-2, p53, and prolifer ating cell nuclear antigen (PCNA) was classified as follows: (-), no reacti ve cells; (+), scattered positive cells; (2+), nests of positive cells; (3), diffuse positive cells. RESULTS. Patients with low grade MALT lymphoma (LG) tended to be positive f or H. pylori (6 of 9), to localize within the submucosa (7 of 9), not to ha ve lymph node involvement (7 of 8), and to have lower tumor stage compared with patients with high grade MALT components (NG). Bcl-2 protein was expre ssed with high frequency by LG (7 of 9). Strong expression of p 53 was more common in the HG tumors (4 of 14), and strong expression of PCNA showed a significant difference between LG (1 of 8) and HG patients (12 of 13). Inve stigation of the patients with long term follow-up (n = 4) revealed that LG remained superficial for a long time and showed gradual progression. Most of these rumors were Bcl-2+/p53-similar to +/-/PCNA-similar to+. There were two patients whose superficial LG (sm/Bcl-2+/p53-/PCNA-similar to+) regres sed after the disappearance of H. Pylori. On the other hand, one patient de veloped ulcerated LG (sm/Bcl-2-/p53+/PCNA3+) after disappearance of H. pylo ri. The authors found complete regression of MALT lymphoma in 9 of 11 patie nts after H. pylori eradication. Initial tumors of these 9 patients were su perficial/sm/n(-)/low grade/Bcl-2+similar to +/-/p53-similar to+ (n = 9), / PCNA-similar to+(n = 6), /PCNA 2+ (n = 3). Two local recurrence and one non -Hodgkin lymphoma in other sites were observed after initial therapy. CONCLUSIONS. Gastric MALT lymphoma with (H. pylori positive/superficial/sm/ low grade/Bcl-2+/p53-similar to+/PCNA-similar to+) pattern will disappear a fter a patient is cured of H. pylori infection. Cancer 2000;88:2210-9. (C) 2000 American Cancer Society.