Diffuse Large B Cell Lymphoma, Disease Patterns, Treatment Paradigms and Clinical Outcomes. a Single Center Study from United Arab Emirates (UAE)

Introduction:

DLBCL is an aggressive B cell lymphoma. Despite increased understanding of the biology of the disease the treatment paradigm for front line therapy has not changed over the past twenty years (RCHOP or its variations) until recent approval of Polatuzumab vedotin-piiq for international prognostic Index (IPI) 2 or greater. Despite having been identified as one of the most common non-Hodgkin's lymphomas in the UAE, Data from the middle east countries regarding disease pattern, treatment paradigms and clinical outcome is lacking. This retrospective study aimed to analyze and generate data from a single institution public referral hospital from UAE.

Methods:

After approval from the Institutional review board (IRB), Patients aged 18 and older with DLBCL were included in this retrospective analysis from January 2022 till June 2024. Data was abstracted from the Electronic medical records (EMR) with regards to patient demographics, disease (biology, stage), treatment and outcomes.

Results:

We identified 41 patients during the study period who were seen with diagnosis of DLBCL.

Median Age of patients at presentation was 48 years. Most of the patients were male (66%) with a Male to Female ratio of 1.93:1.

Molecular subtype (Hans Algorithm) distinguished 8 patients (20%) with ABC type DLBCL, and 16 patients (39%) with GCB type DLBCL. Two patients had High grade B cell lymphoma Double/Triple Hit. Molecular subtype of 15 patients (36%) were not identified.

Staging showed early stage (1-2) N= 9 (22%) while advanced stage disease was seen in 31 patients (78%). Data was not available for one patient.

Risk Stratification with Revised International prognostic Index (R-IPI) showed Poor Risk group (IPI 3-5) 20, Good Risk 14, Very Good Risk 4. Score could not be calculated due to lack of data in 3 patients.

Majority of the patients were treated with RCHOP n= 22 while others were treated with Pola RCHOP n=13. A cohort of the patient received other regimens (CHOP, CHOEP, DA REPOCH, R CODOX M/IVAC). Etoposide containing regimens were used in patients who had Hemophagocytic lymphohistocytic (HLH) presentation alongside the underlying DLBCL while patients with double hit Lymphoma's were treated with DA REPOCH of R CODOX M/R IVAC.

6 patients died of treatment or disease related complications before the end of induction therapy.

With a median follow-up of 310 days (range 41-624 days), the Over all Response Rate (ORR) was 81% with Complete Remission (CR) 75% (N=25) while two patients had Partial Response (PR). Six patients failed induction therapy including the two patients with DH/TH Lymphoma. The remaining 8 patients were of those who expired or left prematurely against medical advice, so there is no recorded response to treatment.

Conclusions

The median age is approximately two decades younger than western literature. There were almost twice as many males than female patients, which is akin to the SEER results of rate of incidence per 100,000 in 2012-2016 of Non-Hodgkin's Lymphomas.

Majority of the patients presented with advanced stage (78%), poor risk IPI disease (50%).

Complete Remission (CR rate) of 75% is comparable to international published data. Disease free remission cannot be estimated due to short follow-up.

Treatment options for DLBL DH/TH remains poor and novel therapeutic paradigm is needed.

McCarthy:BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees.