DEPTH OF INFILTRATION OF PRIMARY GASTRIC B-CELL LYMPHOMAS - CORRELATIONS WITH PROLIFERATION, APOPTOSIS AND EXPRESSION OF P53 AND BCL-2

Local extension has been shown to be a major prognostic factor in prim ary gastric B-cell lymphoma. In order to evaluate whether this paramet er might be correlated with cell proliferation or its regulation, a re trospective study was performed. Fifty-three surgical specimens with p rimary gastric B-cell lymphomas were analysed concerning histological grading, depth of infiltration and Ann-Arbor stage. lit addition, immu nohistochemistry (p53 [Do7], bcl-2 [bcl-2-124], Ki-67 [MiB1]) and in s itu end-labeling (apoptotic bodies) were applied. The depth of infiltr ation was significantly correlated with Ann-Arbor stage (p < 0.001) an d histological grading (p < 0.002). Furthermore, the semiquantitativel y evaluated expressions of Ki-67, apoptotic bodies and p53 revealed th at tumours limited to the mucosa and submucosa had lower numbers of st ained cells than lymphomas infiltrating the muscularis propria or beyo nd (p < 0.001 in all cases). Analysis of bcl-2 expression showed an in verse picture (p < 0.05). The importance of local spread of gastric ly mphomas is underscored by our findings: in gastric lymphomas infiltrat ing the muscularis propria or beyond, powerful proliferative stimuli h ave been acquired, e.g. associated with p53 mutations, that are indepe ndent of the known mucosa-associated stimuli, Helicobacter pylori and autoimmunity.