Aim: Since clinical and prognostic heterogeneity is observed in diffuse large B-cell lymphoma (DLBCL) patients, it is vital to determine its prognostic and predictive factors. The frequency of these factors varies geographically and ethnically. We aimed to reevaluate and discuss the prognostic and predictive factors of DLBCL patients who have been treated with R-CHOP in our center based on the WHO 2017 revised 4th edition. We also investigated the incidence of EBV in DLBCL-NOS.
Patients and Methods: Patients with DLBCL-NOS diagnosed previously in our hospital between 2007-2017 and treated with R-CHOP were included in the study. We evaluated the expressions of CD10, CD5, CD30, BCL-2, BCL-6, MUM-1, MYC, LMP-1, EBNA-2, Ki-67, and p53, by immunohistochemistry, and EBV encoded RNA by in situ hybridization in 104 cases of DLBCL-NOS. The Revised International Prognostic Index (R-IPI) score and the overall survival time was calculated.
Results: The study included 56 men (53.8%) and 48 women (46.2%). The median age was 64.5 years. In 59.6% of the patients, the disease had a nodal beginning, whereas in 40.4% of the patients it had an extranodal presentation. High stage (III-IV) was present in 26.5% of the GCB subtype and 43.6% of non-GCB subtype (p=0.049). A high R-IPI score was observed in 40% of GCB subtype and 54.5% of non-GCB subtype (p=0.028). Survival was significantly lower in the non-GCB subtype (log-rank test p=0.003). The EBV frequency was about 3% as it is reported in Western populations. The frequency of DEL status was 8.7%, indicating that it was associated with inferior survival (p=0.045). De novo CD5+ DLBCL ratio as 13% and it was also associated with inferior survival (p=0.013). We also found CD30+ DLBCL ratio as 11.5%, but we could not establish a significant relationship with prognosis.
Conclusion: DLBCL-NOS requires detailed subtyping and elaboration of prognostic factors. The frequency of DEL status and De novo CD5+ DLBCL indicated that it was associated with inferior survival. However, we could not establish a meaningful relationship of CD30+ DLBCL with prognosis. Three EBV positive cases were identified and two of them were classified as ‘EBV positive large B cell lymphoma’ according to the WHO 2017 revised 4th edition.
Keywords: Diffuse Large-Cell Lymphoma; Prognostic Factors; Survival