ABCL-265: Detection of Triple Protein Expression in Diffuse Large B-Cell Lymphoma (DLBCL): A Single-Center Study

Abstract

Background DLBCL is the most common type of NHL. Genetic studies have revealed that one molecular subtype that is resistant to treatment by standard protocols occurs when there are concurrent translocations in the c-Myc, BCL-2, and BCL-6 genes. Objective Our study aimed to detect the presence of triple protein expression in patients diagnosed with DLBCL at the Clinical Oncology Department in Menoufia University Hospital. We also aimed to explore the possible associations between c-Myc, BCL-2, and BCL-6 co-expression (TEL) and clinical, as well as epidemiological, data of included patients. Patients and Methods A tissue microarray platform was constructed using cores from selected areas of each specimen. 2-mm-diameter cores were duplicated and spaced 0.2 mm apart. Several four-micron-thick sections were prepared from blocks. Hematoxylin and eosin slides were reviewed to confirm pathological diagnosis according to criteria defined by WHO, and immunohistochemistry was used for the detection of c-Myc, BCL-2, and BCL-6 expression. Stained slides were assessed for the percentage of cellular expression for each marker. Median expression was used as the threshold value for defining high and low expression for each marker. DLBCL with high expression for c-Myc, BCL-2, and BCL-6 was defined as TEL. Results Tissue microarray blocks were constructed from paraffin blocks of 94 cases with confirmed diagnoses of DCBL. The median age for participants was 56 years. c-Myc, BCL-2, and BCL-6 showed high protein expression in 51% (n=47), 55% (n=51), and 52.7% (n=49), respectively. Median-based triple protein expression constituted 15% of the sample (n=14). TEL was significantly higher in patients with poor ECOG performance status (PS >2), extranodal presentation, and bone marrow infiltration. No associations between TEL and other patient or disease characteristics (age, gender, smoking history, family history, comorbidities, B symptoms, LDH, B2 microglobulin, stage, IPI, IPI risk group, and baseline neutrophil-lymphocyte ratio) were found. Conclusion Triple protein expression lymphoma is not uncommon among the studied sample, constituting around 45.1% of cases. This positive protein expression was commonly found in patients with poor performance status, creating a particular need for new treatment modalities.