Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin's lymphoma (NHL), and constitutes 30-40% of all cases in adults. DLBCL is heterogeneous in terms of its clinical course, and related molecular and genetic features. In the current era of appropriate chemo-immunotherapy, approximately 50%-60% of patients are cured after treatment. DLBCL is characterized by numerous chromosomal changes which are encountered in a high proportion of cases.
Objective: To examine whether the identification of chromosomal changes at time of diagnosis has prognostic significance in DLBCL.
Methods and study population: The study cohort included those patients with DLBCL, diagnosed and treated during 1996-2012 at the Hematology unit in Bnai-Zion Medical Center, Haifa, who had a cytogenetic study performed based on G-banding analysis from the original biopsy at the time of diagnosis.
Results: One hundred and twenty one patients with DLBCL were included and of these 59 also had chromosomal analysis performed from the tumor tissue at diagnosis. The average age of the cohort was 60.9 (21-87) years, and 59.3% were men. Average follow-up was 50.6 months (1-240 months). In 16 of the 59 biopsies (27.1%) lymphoma cells did not grow in vitro and analysis was not performed in these cases. Of the remaining 43 cases with chromosomal analysis: 36 (83.7%) had chromosomal aberrations, which most frequently involved chromosomes 14, 18, 1 and X. There was no difference in outcome between patients with chromosomal changes, including the presence of complex karyotype or hyperdiploidy (defined as > 50 chromosomes), and those with normal karyotype.
Conclusions: Although complex changes in basic chromosomal structure and altered numbers of chromosomes were identified in patients with DLBCL, none of these features were of prognostic significance in terms of overall survival. In the light of these findings, we confirm that in common practice for DLBCL outside of clinical trials there appears to be no advantage to performing routine chromosomal studies on biopsy specimens obtained from patients with newly diagnosed DLBCL.