GASTRIC LYMPHOMAS COMPARED WITH LYMPH-NODE LYMPHOMAS IN A POPULATION-BASED REGISTRY DIFFER IN STAGE DISTRIBUTION AND DISSEMINATION PATTERNSBUT NOT IN PATIENT SURVIVAL

BACKGROUND. Non-Hodgkin's lymphoma (NHL) originating in mucosa-associa ted lymphoid tissue (MALT) is supposed to have different clinical beha vior from lymph node NHL. To test this hypothesis, the authors compare d data of gastric NHL patients with lymph node NHL patients in a popul ation-based registry for differences in clinical presentation and prog nosis. METHODS. Data from 1981-1989 on patients with primary gastric N HL (n = 109) and patients with primary lymph node NHL (n = 658) were r etrieved from a Dutch population-based NHL registry. Patients were com pared for stage distribution, involved sites, and survival. The progno stic value of grading lymphomas according to the malignancy grades of the Working Formulation for Clinical Usage was compared with the value of grading MALT NHLs as either low grade or high grade malignancies. RESULTS. Patients with gastric NHL presented more often with localized disease. Stage IV patients had a higher rate of dissemination to othe r non-lymph node sites but less frequent localization in the bone marr ow. The restricted pattern of dissemination was reflected in a signifi cantly lower recurrence rate for gastric NHL. Gastric NHL patients had significantly better disease free survival than lymph node NHL patien ts (80% and 44% at 5 years, respectively; P < 0.001). In contrast, ove rall survival did not significantly differ between the two groups, and it appeared to depend on disease stage. Grading MALT lymphoma as eith er low grade (26%) or high grade (70%) malignancies did not provide be tter prognostic information than grading according to the Working Form ulation for Clinical Usage (low 8%, intermediate 75%, high 9%). CONCLU SIONS. Primary gastric NHL shows a restricted dissemination pattern, w hich gives support to the MALT lymphoma concept. Although this might e xplain the superior disease free survival observed for gastric NHL pat ients, it does not translate into better overall survival for these pa tients. (C) 1997 American Cancer Society.