Prognostic impact of immunophenotyping of diffuse large B-cell lymphoma - a single-centre experience

Abstract

The concept generated by biological expression profile divided patients with diffuse large B-cell lymphoma (DLBCL) into two subtypes. This concept has been presented in the recent editions of WHO classification and became a prognostic tool. Aim of the study was introduction of new three-marker model for immunohistochemical and prognostic subclasification of patients with DLBCL. Our retrospective study enrolled 200 adult patients with DLBCL diagnosed and treated in the period between January 2013 to January 2021. They were all treated with chemoimmunotherapy with R+/-CHOP regimen and the median follow-up of the patients was 48 months. We analysed the biopsy samples immunohistochemically with the markers of germinal (BCL6) and post-germinal centre (MUM1), and the marker of apoptosis (BCL2). Using the immunohistochemical three-marker model, which consisted of BCL-2, BCL-6, and MUM1, we distributed the patients with DLBCL into 2 subgroups: germinal centre – like (GCL) and activated centre-like lymphoma (ACL). The GCL and ACL patients were comparable regarding age, gender and all other already established prognostic parameters. Patients with GCL had overall survival of 140 months, and patients with ACL had overall survival of 88 months. ACL patients with BCL2 expression had a shorter survival compared to ACL patients without BCL2 expression. The difference in survival was statistically significant for p=0.01914. The study introduced the new three-marker model for immunohistochemical subclasification of patients with DLBCL treated with immunochemotherapy. Apoptotic marker BCL2 is a strong survival predictor. In the present study, we confirmed the prognostic importance of BCL2 protein expression, which showed a predictive capacity in ACL. Keywords: DLBCL, three - marker model, immunohistochemical, BCL2