Prognostic Significance of BCL2 Protein in Diffuse Large Cell Lymphoma of Head and Neck; Relation to Response to Chemotherapy

Abstract

Diffuse large B cell lymphoma (DLBCL) is a heterogeneous disease that displays a highly variable clinical outcome. It is a neoplasm of large transformed B cells with a diffuse growth pattern. DLBCL is the most common type of non-Hodgkin’s lymphoma (NHL) (31% of all cases). Approximately half of patients with DLBCL are cured with current chemotherapy regimens. The purpose of this study was to evaluate BCl2 expression in 45 patients diagnosed with DLBCL of head and neck region and correlate the level of its immunohistochemical expression with different clinicopathological variables with emphasis upon patients’ age, gender, nodal or extra-nodal location of lymphoma, patients’ response to chemotherapy, progression-free survival (PFS) and overall survival (OS). A retrospective analysis of 45 patients diagnosed to have DLBCL. A cut off value of ≥ 50% protein expression denoted BCL2 positivity. Out of 45 cases, 36 cases (80%) revealed BCL2 positive expression and 9 cases (20%) were BCL2 negative. We found statistically significant differences in BCL2 expression regarding different patients’ responses to chemotherapy, patients’ OS and PFS (p ≤ 0.05). No statistically significant differences in BCL2 expression regarding the patients’ Ann Arbor clinical stage, age group and tumor site (nodal or extra-nodal, p > 0.05) using the Chi-square test. BCL2 expression was analyzed in relation to 5 years OS and PFS using Kaplan Meier curves and Log Rank test for survival analysis. Cases that demonstrated BCL2 positivity revealed shortened OS and PFS with highly statistically significant differences among the studied variables (p = 0.000). We also found that patients who respond well to the chemotherapeutic regimen had negative BCL2 expression, the differences were statistically significant (p = 0.015). In conclusion, BCL2 expression could be considered a predictor for patients’ chemotherapeutic response, OS and PFS.