Abstract

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 4^th 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 4^th edition.

Keywords: Diffuse Large-Cell Lymphoma; Prognostic Factors; Survival