Watch and Wait in Mantle Cell Lymphoma

Advances in the treatment of mantle cell lymphoma with BTK inhibitors

Mantle cell lymphoma (MCL) is a heterogenous disease that is one of the most challenging blood cancers due to its poor prognosis, high risk of relapse and drug resistance. Recent researches have brought significant changes in MCL patients outcomes and new clinical. Bruton's Tyrosine Kinase (BTK), a key kinase in the B-cell antigen receptor (BCR) signaling pathway, is a clinical research hot spot and plays a major role in the survival and spread of malignant B cells. The first generation of BTK inhibitors, led by ibrutinib, have shown promising results in targeted treatment. Meanwhile, several inhibitors have entered clinical studies and demonstrated outstanding therapeutic activity in clinical trials for MCL, indicating a good prospect for development. Despite these encouraging findings, the duration of response is limited, and resistance to BTK inhibitors develops in a portion of individuals. This review summarizes the pathogenesis of MCL and targeted BTK inhibitors and provides an overview of the mutations that can lead to resistance to BTK inhibitors. The purpose of this article is to review the literature describing these selective therapies and provides perspectives for their further development.

Mantle Cell Lymphoma Under the Scope of Personalized Medicine: Perspective and Directions

Mantle cell lymphoma (MCL) is a rare, incurable non-Hodgkin's lymphoma characterized by naive B cells infiltrating the lymphoid follicle's mantle zone. A key feature of MCL is the cytogenetic abnormality t(11;14) (q13:q14), found in 95% of cases, leading to Cyclin D1 overexpression resulting in uncontrolled cell cycle progression and genetic instability. Occasionally, Cyclin D2 or D3 overexpression can substitute for Cyclin D1, causing similar effects. The transcription factor SOX11 is a hallmark of classical Cyclin D1-positive MCL and also in cases without the typical t(11;14) abnormality, making it an important diagnostic marker. MCL's development necessitates secondary genetic changes, including mutations in the ATM, TP53, and NOTCH1 genes, with the TP53 mutation being the only genetic biomarker with established clinical prognostic value. The Mantle Cell Lymphoma International Prognostic Index (MIPI) score, which considers age, performance status, serum LDH levels, and leukocyte count, stratifies patients into risk groups. Histologic variants of MCL, such as classic, blastoid, and pleomorphic, offer additional prognostic information. Recent research highlights new mutations potentially tied to specific populations among MCL patients, suggesting the benefit of personalized management for better predicting outcomes like progression-free survival. This approach could lead to more effective, risk-adapted treatment strategies. However, challenges remain in patient stratification and in developing new therapeutic targets for MCL. This review synthesizes current knowledge on genetic mutations in MCL and their impact on prognosis. It aims to explore the prognostic value of genetic markers related to population traits, emphasizing the importance of tailored molecular medicine in MCL.

B-cell non-Hodgkin lymphomas

B-cell lymphomas occur with an incidence of 20 new cases per 100 000 people per year in high-income countries. They can affect any organ and are characterised by heterogeneous clinical presentations and courses, varying from asymptomatic, to indolent, to very aggressive cases. Since the topic of B-cell non-Hodgkin lymphomas was last reviewed in The Lancet in 2017, a deeper understanding of the biological background of this heterogeneous group of malignancies, the availability of new diagnostic methods, and the development and implementation of new targeted and immunotherapeutic approaches have improved our ability to treat patients. This Seminar provides an overview of the pathobiology, classification, and prognostication of B-cell non-Hodgkin lymphomas and summarises the current knowledge and standard of care regarding biology and clinical management of the most common subtypes of mature B-cell non-Hodgkin lymphomas. It also highlights new findings in deciphering the molecular background of disease development and the implementation of new therapeutic approaches, particularly those targeting the immune system.

Clinical characteristics and outcomes of ocular adnexal mantle cell lymphoma

PURPOSE

To compare characteristics of initial ocular adnexal (OA) mantle cell lymphoma (MCL) and initial systemic MCL.

METHODS

Retrospective, comparative case series. Patients treated for MCL at Mayo Clinic from 1/1/1990 to 11/30/2020. MCL was classified as initial OA if first site was OA or initial systemic if first site was elsewhere with progression or recurrence to the OA region.

OUTCOME MEASURES

Features, treatment, and survival.

RESULTS

There were 50 patients with MCL, 23 initial OA and 27 initial systemic. Patients with initial OA MCL had more conjunctival (52% vs. 19%, p = .017) involvement and less frequently received chemotherapy plus autologous stem cell transplant (ASCT) (9% vs. 33%, p = .046) as initial treatment. Complete remission was achieved in 41 (91% vs. 74%, p = .152) patients. Five-year disease-specific survival was similar in initial OA and initial systemic MCL (92% vs. 83%, p = .187). Subanalysis of patients with initial OA MCL revealed 9 (39%) patients developed tumor recurrence, with mean time to recurrence of 28 months. Comparison (no recurrence vs. recurrence) of initial OA MCL patients revealed those with no recurrence had shorter mean final follow-up (3.3 vs. 9.8 years, p = .005) and more frequent initial treatment with rituximab-based chemotherapy plus ASCT (43% vs. 0%, p = .048). Recurrence had no effect on the 5-year age-adjusted risk of death from lymphoma (HR 2.17, 95% CI 0.55-9.09, p = .266).

CONCLUSIONS

Initial OA and initial systemic MCL patients differ in presentation and management but have similar survival.

Mantle Cell Lymphoma with Chronic Lymphocytic Leukemia-Like Features: A Diagnostic Mimic and Pitfall

Mantle cell lymphoma (MCL) is a mature B-cell neoplasm characterized by t(11;14)(q13;q32) and cyclin D1 overexpression in >95% of cases. Classic MCL cases are composed of a monotonous population of small to medium-sized lymphocytes with irregular nuclear contours that are positive for cyclin D1 and SOX11, and negative for CD23 and CD200. By contrast, occasional MCL cases express CD23 and CD200 but lack of SOX11, and morphologically and immunophenotypically resemble chronic lymphocytic leukemia (CLL), termed as CLL-like MCL in this study. These neoplasms pose a diagnostic challenge and easy to be diagnosed as CLL in daily practice. We studied 14 cases of CLL-like MCL to define their clinicopathologic features and compared them with 33 traditional CLL cases. There were 8 men and 6 women with a median age of 62 years (range, 44-80). Compared with CLL, patients with CLL-like MCL have lower levels of peripheral blood and bone marrow involvement, and more frequently had mutated IGHV. Immunophenotypically, CLL-like MCL often showed moderate to bright expression of B-cell antigens and surface immunoglobulin light chain, dim and partial expression of CD23 and CD200, infrequent CD43 positivity, and lack of LEF1. The overall survival of patients with CLL-like MCL was similar to that of CLL patients. In conclusion, CD23+, CD200+, and SOX11-negative MCL closely resemble CLL, both clinically and pathologically, including a similar indolent clinical course. They may pose a diagnostic challenge. However, patients with CLL-like MCL also have distinctive immunophenotypic features that are useful to distinguish these neoplasms from CLL.

Exploiting gene mutations and biomarkers to guide treatment recommendations in mantle cell lymphoma

INTRODUCTION

While there has been an improvement in the treatment of mantle cell lymphoma (MCL) in both median progression-free survival (PFS; >7-8 years) and overall survival (OS; >10-12 years), patients with high-risk features such as high risk MIPI (mantle cell international prognostic index), high Ki-67 (≥30%), or blastoid variants still carry poor outcome with a median OS of 3 years. Furthermore, patients with high-risk molecular features, such as TP53 mutations, show dismal outcome, with a median OS of 1.8 years, regardless of therapy used. Further studies have led to the development of six novel drugs approved for the treatment of relapse/refractory (R/R) MCL, leading to improved survival even in refractory or high-risk patients.

AREAS COVERED

This review covers clinical biological and molecular features that impact MCL outcome with current standards. Beyond the recognition of separate subentities, we review how high-risk molecular features have paved the way towards a new paradigm away from chemoimmunotherapy.

EXPERT OPINION

Progress in novel therapies and in routine diagnostics, particularly next-generation sequencing (NGS), support the development of new treatment strategies, not based on the dose intensity/age dichotomy, which may prevent the need for chemotherapy and improve outcome across MCL including in high-risk subsets.

Mantle cell lymphoma - advances in molecular biology, prognostication and treatment approaches

Mantle cell lymphoma (MCL) is clinically characterised by its heterogenous behaviour with courses ranging from indolent cases that do not require therapy for years to highly aggressive MCL with a very limited prognosis. A better understanding of the complex biology of MCL has already led to the approval of several innovative agents, expanding the landscape of MCL therapies and improving therapeutic options especially for refractory/relapsed (R/R) disease. Nevertheless, to further optimise MCL treatment, early identification of individual risk profile and risk-adapted, patient-tailored choice of therapeutic strategy needs to be prospectively incorporated into clinical patient management. The present review highlights recent advances in deciphering the molecular background of MCL, the definition of prognostically relevant factors and the identification of potential druggable targets and summarises current treatment recommendations for primary and R/R MCL including novel targeted therapies.