CLINICAL-SIGNIFICANCE OF BCL2 AND P53 PROTEIN EXPRESSION IN DIFFUSE LARGE B-CELL LYMPHOMA - A POPULATION-BASED STUDY

Purpose: We studied the prognostic significance of bcl2 and p53 protei n expression in relation to clinical and pathologic characteristics in patients with diffuse large B-cell lymphoma (LCL). Patients and Metho ds: Three hundred seventy-two patients with LCL were retrieved from a population-based registry for non-Hodgkin's lymphoma (NHL). bcl2 and p 53 protein expression was studied on paraffin-embedded tumor tissue by immunohistochemistry in relation to clinical factors, Response to the rapy and survival were analyzed in 165 patients who were uniformly sta ged and treated and for whom all prognostic data were available accord ing to the International Prognostic Index (IPI). Results: Forty-five p ercent of tumors showed strong expression of the bcl2 protein (bcl2++) , with a higher frequency in patients with primary nodal involvement, Disease-free survival (DFS) was significantly better in bcl2-negative/ intermediate (bcl2-/+) cases as compared with bcl2++ cases (P = .0011) . At 5 years, bcl2-/+ patients showed a DFS rate of 74%, in contrast t o bcl2++ patients with a DFS rate of 41% (P = .002). Bcl2 was the stro ngest independent prognostic value in a multivariate analysis, with a relative risk (RR) of 3.0 in comparison to p53 expression and the clin ical factors of the IPI, Overall survival (OS) was not significantly i nfluenced by bcl2 protein expression. p53 protein expression was found in 13% of cases, with a higher frequency in patients with extensive d isease. p53 expression did not influence the chance to achieve complet e remission (CR) and survival. Conclusion: bcl2 protein is frequently expressed in LCL and is a strong independent prognostic factor for DFS . p53 expression is related with high tumor burden, but is not an inde pendent risk factor for CR and survival.