Evaluating upfront high-dose consolidation after R-CHOP for follicular lymphoma by clinical and genetic risk models

Age and lymphocyte/monocyte ratio as prognostic factors for autologous transplantation in the treatment of patients with follicular lymphoma

OBJECTIVE

Follicular lymphoma (FL) is an indolent, lymphoproliferative disease of B-cell origin that has a heterogeneous disease course with varying outcomes. Certain patients may undergo autologous stem cell transplantation. We investigated the outcome of autologous stem cell transplantation in patients with FL.

METHODS

Patients who received autologous stem cell transplantation at the University of Debrecen's Department of Hematology between 2004 and 2021 were retrospectively analyzed. The overall survival (OS) and progression-free survival (PFS) after transplantation of patients with FL were examined. Prognostic factors that may influence the course of the disease were chosen.

RESULTS

Data were collected from 49 patients. OS was influenced only by age, whereas PFS was affected by age and the lymphocyte/monocyte ratio. The combination of age and lymphocyte/monocyte ratio defined a patient population with a particularly unfavorable prognostic risk profile: patients over 47 years of age with a pre-transplant lymphocyte/monocyte ratio greater than or equal to 2.675.

CONCLUSION

Age and lymphocyte/monocyte ratio were identified as useful prognostic factors for PFS in patients with FL following autologous stem cell transplantation.

Genetic subdivisions of follicular lymphoma defined by distinct coding and noncoding mutation patterns

Follicular lymphoma (FL) accounts for ∼20% of all new lymphoma cases. Increases in cytological grade are a feature of the clinical progression of this malignancy, and eventual histologic transformation (HT) to the aggressive diffuse large B-cell lymphoma (DLBCL) occurs in up to 15% of patients. Clinical or genetic features to predict the risk and timing of HT have not been described comprehensively. In this study, we analyzed whole-genome sequencing data from 423 patients to compare the protein coding and noncoding mutation landscapes of untransformed FL, transformed FL, and de novo DLBCL. This revealed 2 genetically distinct subgroups of FL, which we have named DLBCL-like (dFL) and constrained FL (cFL). Each subgroup has distinguishing mutational patterns, aberrant somatic hypermutation rates, and biological and clinical characteristics. We implemented a machine learning-derived classification approach to stratify patients with FL into cFL and dFL subgroups based on their genomic features. Using separate validation cohorts, we demonstrate that cFL status, whether assigned with this full classifier or a single-gene approximation, is associated with a reduced rate of HT. This implies distinct biological features of cFL that constrain its evolution, and we highlight the potential for this classification to predict HT from genetic features present at diagnosis.

Follicular lymphoma: an update on biology and optimal therapy

Follicular lymphoma (FL) is a mature B-cell neoplasm with a mostly indolent course. Genetic hallmark characteristics are Bcl-2 overexpression based on a t(14;18) translocation and additional secondary genetic and epigenetic aberrations. Standard treatment for early-stage patients has curative intent and usually consists of radiotherapy with or without rituximab. In the advanced stage, the main therapeutic focus is on prolonged remissions. Therefore, treatment in asymptomatic patients is usually deferred. Symptomatic patients are subject to immunochemotherapy induction followed by antibody maintenance. Importantly, about one in five patients subsequently experiences a more rapid clinical course, achieving only short remissions with multiple relapses (POD24). In those patients, there is still an urgent need for improved therapeutic options. Accordingly, a plethora of targeted and immunotherapeutic options, including immunomodulatory drugs, small molecule inhibitors, monoclonal antibodies as well as bispecific T-cell engager antibodies and CAR-T cell products have been recently evaluated in such relapsed high-risk patients.

Past, present and future of prognostic scores in follicular lymphoma

Although most follicular lymphoma (FL) patients have prolonged survival, the identification of those at risk of early progression, multiple relapses or histological transformation is essential for the improvement of long-term outcomes. In this sense, a plethora of prognostic indexes have been developed in the last decades. However, determining which one is more accurate and clinically meaningful remains a challenge. Key factors for the external validity of available indexes include characteristics of the study population, treatment intervention, and design of the study. While initial risk scores were composed of clinical, biochemical, and hematological variables, genomic and imaging data have been incorporated in recent years. Despite an obvious step forward in the knowledge of the natural history and biology of FL, predictions remain inaccurate. Further research will likely incorporate information from circulating tumor DNA and artificial intelligence models to refine the prognostic classification of the heterogeneous FL population.