Prognostic Significance of Bcl-2 and p53 Protein Expressions and Ki67 Proliferative Index in Diffuse Large B-cell Lymphoma

Objective: Diffuse large B-cell lymphoma (DLBCL) is a high-grade neoplasm that has heterogeneous properties in clinical, morphological, and immunophenotypic aspects. In the present study the effects of p53, Bcl-2, and Ki67 on prognosis and their relationships with clinical parameters were examined. Materials and Methods: Thirty-five patients who had been diagnosed with nodally located DLBCL at İzmir Atatürk Training and Research Hospital between January 1999 and June 2006 were included in the study. The Ann Arbor classification system was used to determine the stage of the patients. The patients were evaluated according to age, sex, stage, B symptoms, extranodal involvement, and lactate dehydrogenase (LDH) level as well as immunohistochemically. P53 protein and Bcl-2 oncoprotein expressions and Ki67 proliferation index were assessed immunohistochemically. Results: High Bcl-2 expression was found in 9 patients (25.7%), high p53 expression was found in 10 patients (28.6%), and high Ki67 was observed in 23 patients (65.7%). There was no significant correlation between p53 expression, Bcl-2 expression, or Ki67 proliferation index and age, sex, stage, B symptoms, extranodal involvement, LDH level, and overall survival (p>0.05). We did not find a relationship among p53 expression, Bcl-2 expression, Ki67 proliferation index, and prognosis (p>0.05). There was no significant relationship between overall survival and age, sex, stage, B symptoms, extranodal involvement, or LDH level (p>0.05). Our results revealed that Bcl-2 and p53 protein expressions and Ki67 proliferation index have no effect on overall survival of patients with DLBCL. Conclusion: The prognostic importance of p53 and Bcl-2 protein expressions and Ki67 proliferation index in DLBCL, which has biological and clinical heterogeneity, can be understood in a large series of studies that have subclasses and immunohistochemical markers with optimal cut-off values.