The t(14;18) Is Associated with Germinal Center Phenotype Subset of the Diffuse Large B-Cell Lymphoma Patients in Egypt.

Diffuse large B-cell lymphoma (DLBCL) is a generic term for clinically and biologically heterogeneous group of tumors. Identification of high risk patients at presentation will allow effective trials of treatment. Therefore, t(14;18) detection using interphase Florescence in Situ Hybridization (FISH) and Biomed multiplex polymerase chain reaction (PCR) was done on formalin fixed paraffin embedded lymph node archives from pathology department, National Cancer Institute, Cairo, Egypt. Diagnosis were confirmed by pathological review using the diagnostic criteria defined in the revised European-American Classification of Lymphoid Neoplasm / WHO classification. The study was carried out on 26 patients with lymph screen CD 19 +/ CD 5 - / CD 10 ± correlating t(14;18) with the immunophenotypic biological variables, Immunohistochemistry, and the standardized international prognostic index (IPI) with a median follow up for 5 years. Comparison of FISH and PCR techniques showed identical specificity with advantageous sensitivity of FISH over the PCR. Nine patients out of eleven with t(14;18) were associated with Germinal Center (GC) phenotype (CD10+ /Bcl-6 +). However, Only two out of fifteen with non GC phenotype(CD10- /Bcl-6 -) were associated t(14;18). The mean 5 years survival time of patients with t(14;18) was significantly lower (31.18 ± 3.06 month) compared to those without translocation (54.32 ± 2.54 month) (P=0.001). Interestingly, patients with t(14;18) showed Bcl-2 positive (100%) compared to 46.6% in patient without t(14;18) (P=0.004). There is a significant correlation between t(14;18) and the clinicopathological risk criteria of IPI(P=0.01). In our study we demonstrated a detection of t(14;18) by FISH was found to be superior to PCR. The high risk group of GC phenotype together with Bcl-2 expression were associated with t(14;18) and could be used to tailor treatment.