Clinicopathological spectrum of Diffuse Large B Cell lymphoma: a study targeting population yet unexplored in Pakistan

Clinicopathological Spectrum of B-Cell Non-Hodgkin Lymphoma in Pakistan Population: A Single-Center Study

Background B-cell non-Hodgkin lymphoma (NHL) is a common malignancy worldwide and in the Pakistani population. In our population, there was limited information regarding the clinicopathological characteristics of B-cell NHL. This study assessed the disease spectrum and most prevalent subtypes of B-cell NHL. Methodology An analysis of 548 cases was conducted in this cross-sectional study between January 2021 and September 2022, using a non-probability consecutive sampling approach. Patient age, gender, site of involvement, and diagnosis were documented according to the 5th edition of the World Health Organization (WHO) Classification of Tumors of Hematopoietic and Lymphoid Tissue, published in 2018. Data were entered and analyzed using Statistical Product and Service Solutions (SPSS) (IBM SPSS Statistics for Windows, Version 26.0, Armonk, NY). Results The mean age of the patients was 47.73±20.44 years. There were 369 males (67.34%) and 179 females (32.66%). The most prevalent type of B-cell NHL was diffuse large B-cell lymphoma (DLBCL) (58.94%), followed by chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (13.14%), Burkitt lymphoma (9.85%), and precursor B-cell lymphoblastic lymphoma (5.11%). In contrast to low-grade B-cell NHL (22.99%), high-grade B-cell NHL was more common (77.01%). Nodal involvement was observed in 62.04% of cases. The cervical region was the most common nodal site of involvement (62.04%), and the gastrointestinal tract (GIT) was the most common extranodal site (48.29%). Conclusion The incidence of B-cell NHL is higher in older age groups. The most common nodal site was the cervical region, whereas the extranodal site was the GIT. The most reported subtype was DLBCL, followed by CLL/SLL, and Burkitt lymphoma. The prevalence of high-grade B-cell NHL is higher than that of low-grade B-cell NHL.

No difference in treatment outcome between patients with nodal versus extranodal diffuse large B-cell lymphoma

Background and Aim

Diffuse large B-cell lymphoma (DLBCL) has been classified using various parameters, including the site of origin. Studies have reported conflicting outcomes when DLBLC patients were stratified according to the site of origin. This study aimed to investigate the response rate and survival outcomes in nodal versus extranodal DLBCL and compare the results to a region-matched study covering the 1988 - 2005 period.

Methods

A single-center retrospective cohort study was conducted on all patients diagnosed with DLBCL and treated in a tertiary care hospital in Pakistan during 2014 - 2019. We calculated the mean and median for continuous variables and frequency and percentages for all categorical variables. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier survival curves. A Cox proportional hazards model was used to determine the hazard ratio (HR) for OS.

Results

Of the 118 patients, 49 patients (41.5%) had nodal disease and 69 patients (58.5%) were diagnosed with extranodal DLBCL. The majority of patients in the nodal and extranodal cohorts presented with Stages III and IV disease (73.4% and 62.3%, respectively). A complete response to (immuno) chemotherapy was achieved in 71.4% of nodal DLBCL patients and 65.2% of extranodal DLBCL patients. The 5-year PFS and median PFS in the entire cohort were 0.8% and 17 m, respectively. The PFS and median PFS in the nodal and extranodal DLBCL cohort were 0% and 1.4%, respectively, and 15 m and 19 m, respectively. The 5-year OS and median OS in the entire cohort were 16.1% and 19 m, respectively. The OS and median OS in the nodal and extranodal DLBCL cohort were 8.2% and 21.7%, respectively, and 19 m and 21 m, respectively. Multivariable linear regression revealed that the ABC phenotype (nodal, HR = 1.37, 95% CI = 1.37 - 3.20; extranodal, HR = 1.65, 95% CI = 1.46 - 3.17; GBC as reference) and double and triple hit DLBCL (nodal, HR = 1.29, 95% CI = 1.19 - 2.81; extranodal, HR = 1.87, 95% CI = 1.28 - 2.43; and non-expressors as reference) are independent negative predictors of OS.

Conclusions

DLBCL incidence in the Karachi region has remained comparable but patient composition in the extranodal DLBCL cohort has shifted to predominantly advanced stage. Nodal and extranodal DLBCL were associated with similar PFS and OS profiles and first- and second-line treatment responses. Cell of origin and antigen expression status was independent negative predictors of OS, disfavoring the ABC phenotype and lesions with c-MYC and BCL2 and/or BCL6 overexpression.

Relevance for Patients

DLBCL is an aggressive type of non-Hodgkin's lymphoma, however; patients respond well to standard systemic chemotherapy. Extranodal type of DLBCL patients tend to have more residual disease after first-line systemic chemotherapy, but physicians should keep in mind that the subsequent line treatment mitigates its negative impact on survival.

Clinicopathological Spectrum of Hodgkin's and Non-Hodgkin's Lymphoma: A Tertiary Care Cancer Hospital Study in Pakistan

Introduction

Lymphomas are a heterogeneous group of disorders that arise primarily from lymphoid tissue and are categorized based on histological features and immunophenotypes. The distribution and frequency of different types of lymphoma vary in different parts of the world. This study aimed to document the frequency and clinicopathological characteristics of various types of lymphoma in our population to understand the ever-increasing burden of disease and formulate the optimal management and prevention plans.

Materials and methods

This study was conducted at Nuclear Medicine, Oncology and Radiotherapy Institute (NORI) from August 2015 to March 2022. A total of 300 cases of lymphoma that were diagnosed and treated at NORI were included in the study. We measured the frequency of different lymphomas and patient age, sex, and stage IV presentation at the time of diagnosis. IBM SPSS Statistics for Windows, Version 23.0 (Armonk, NY: IBM Corp.) was used to analyze the data.

Results

Three hundred patients with lymphoma were included in the study. There were more non-Hodgkin’s lymphoma (NHL) cases (n=224; 74.6%) than Hodgkin’s lymphoma (HL) cases (n=76; 25.3%). T-cell NHL was seen in 11 cases (4.8%), while B-cell NHL was found in 214 cases (95%). Diffuse large B-cell lymphoma was the predominant type (n=156; 69.3%). Among T-cell lymphomas, anaplastic T-cell lymphoma was the most common subtype (n=6; 2.6%) followed by angioimmunoblastic T-cell lymphoma (n=2; 0.8%) and T-cell lymphoblastic lymphoma (n=1; 0.4%). For classical HL, mixed cellularity was the predominant type (n=38; 50%) followed by nodular sclerosis (n=31; 40.8%), lymphocyte depleted (n=5; 6.6%), and lymphocyte rich (n=2; 2.6%). Stage IV was present in 21 HL cases (27.6%), and stage IV was seen in 67 NHL cases (29.7%) at the time of diagnosis. Most HL and NHL patients were male. Most HL cases presented in the younger age group (aged 15 to 35 years), while the largest group of NHL patients were aged 56 to 75 years.

Conclusion

Our population has a broad spectrum of lymphoma and its subtypes. NHL is more common than HL, and the frequency of B-cell NHL is higher than that of T-cell NHL. Approximately one-third of the patients presented in stage IV at the time of diagnosis. An awareness of clinicopathological characteristics of lymphoma in our setup would aid in diagnosis, formulating standard management plans, and prevention strategies for optimal patient outcomes.