Recent advances in understanding and managing T-cell lymphoma

Owing to the rarity of peripheral T-cell lymphoma (PTCL) and the heterogeneity of subtypes, there are no compelling data to guide the therapeutic approaches for such patients. Over the years, there have been remarkable advances in molecular subtyping and treatment of PTCL, although there are still many areas to be explored. In this review, we summarize recent updates on the evolution of understanding and treatment for PTCL.

Novel treatment avenues for peripheral T-cell lymphomas

INTRODUCTION

Peripheral T-cell lymphomas (PTCLs) and natural killer (NK) or T-cell non-Hodgkin's lymphomas (NHLs) are a rare and heterogeneous class of diseases with generally poor prognosis. This work intends to provide a focused primer on clinical diagnosis, current treatment regimens, and novel therapeutic approaches. The recent WHO classification has defined 18 different subtypes of PTCL and NK T-cell lymphomas. Diagnosis is mainly based on histology, flow-cytometric analysis of surface molecules in the blood and bone marrow, cytogenetics/fluorescence in situ hybridization (FISH), and T-cell receptor (TCR) rearrangement. Staging as well as follow-up diagnostic procedures rely on imaging techniques such as computerized tomography (CT) and positron emission tomography (PET). Current chemotherapeutic regimens such as CHOP result in a 60 - 70% response rate; however, 5-year survival is only around 30%. Therefore, new treatment strategies are urgently needed. Currently, different drug classes are under scrutiny.

AREAS COVERED

The authors discuss substances that directly target the tumor cells. The article includes such substances as antimetabolites, antibodies, histone deacetylase inhibitors, tyrosine kinase inhibitors, and immunomodulatory substances such as lenalidomide.

EXPERT OPINION

In the future a close collaboration of geneticists, biochemists, and clinicians together with new technologies such as deep sequencing will allow the refinement of treatment strategies in many diseases including PTCLs and NHLs. This refinement will allow treatments to be prepared according to the need of the individual patient.

Bortezomib in combination with CHOP as first-line treatment for patients with stage III/IV peripheral T-cell lymphomas: a multicentre, single-arm, phase 2 trial

BACKGROUND

We performed a phase II study to evaluate the efficacy of bortezomib in combination with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) as first-line treatment for patients with stage III/IV peripheral T-cell lymphomas (PTCLs) based on our phase I study results.

METHODS

Patients received bortezomib on days 1 and 8 at a dose of 1.6 mg/m(2) in addition to CHOP every 3 weeks for a total of six cycles.

RESULTS

Forty-six patients were enrolled: PTCL, not otherwise specified (PTCL-NOS, n=16), extranodal NK/T-cell lymphoma, nasal type (ENKTL, n=10), angioimmunoblastic T-cell lymphoma (AITL, n=8), ALK-negative anaplastic large-cell lymphoma (ALCL, n=6), cutaneous T-cell lymphoma (CTCL, n=5) and hepatosplenic T-cell lymphoma (n=1). Thirty patients achieved complete response (CR, 65%) and the overall response rate was 76% (35/46). Although the CR rate of ENKTL was only 30% (3/10), three subtypes of PTCLs (PTCL-NOS, AITL and ALCL) showed 87% of overall response rate (ORR) (26/30) and 73% of CR rate (22/30). However, the 3-year overall survival and progression-free survival were 47% and 35%, respectively due to frequent relapse after remission. Grade 3/4 leucopenia was the most frequent toxicity whereas neurotoxicity was tolerable: grade 1 or 2 of peripheral neuropathy.

CONCLUSIONS

The combined treatment of bortezomib and CHOP is an effective and feasible regimen for advanced-stage PTCLs other than ENKTL, with acceptable toxicity. However, future studies exploring new drug combinations are warranted to overcome relapse after remission.

Update: peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) are a group of biologically heterogeneous but typically aggressive diseases. Progress in understanding and developing optimal therapies for PTCLs has been hampered by disease rarity and only relatively recent recognition of the importance of the T-cell phenotype. The International Peripheral T-cell Lymphoma Project was a large collaborative effort to provide a broader understanding of prognosis. Recently, several new therapies have shown promise in the treatment of PTCLs.

Therapies for Peripheral T-Cell Lymphomas

Peripheral T-cell lymphomas (PTCLs) are a rare and heterogeneous group of disorders that, for the most part, are associated with a very poor prognosis. The standard therapy for PTCLs is CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or a comparable CHOP-like regimen that incorporates anthracyclines. With the exception of anaplastic lymphoma kinase–positive anaplastic large cell lymphoma (ALK+ ALCL), the cure rate for PTCLs with CHOP is low, and limited evidence suggests that anthracyclines do not improve the prognosis. However, there is no compelling evidence that any other regimen or approach is superior. It remains challenging to compare alternative therapies or treatment strategies with CHOP because the majority of data are retrospective and include diverse patient populations. Recently, prospective studies have been initiated exclusively for PTCL, and in some, select histologic subtypes are evaluated in an effort to remove heterogeneity. Encouragingly, there have been several new therapies emerging with activity in PTCLs and exciting novel combinations under consideration that will hopefully move the field forward and improve outcome in this challenging group of diseases.

Peripheral T-cell lymphoma

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of clinically aggressive diseases associated with poor outcome. Studies that focus specifically on PTCL are emerging, with the ultimate goal of improved understanding of disease biology and the development of more effective therapies. However, one of the difficulties in classifying and studying treatment options in clinical trials is the rarity of these subtypes. Various groups have developed lymphoma classifications over the years, including the World Health Organization, which updated its classification in 2008. This article briefly reviews the major lymphoma classification schema, highlights contributions made by the collaborative International PTCL Project, discusses prognostic issues and gene expression profiling, and outlines therapeutic approaches to PTCL. These include the standard chemotherapeutic regimens and other modalities incorporating antifolates, conjugates, histone deacetylase inhibitors, monoclonal antibodies, nucleoside analogs, proteasome inhibitors, and signaling inhibitors. As this review emphasizes, the problem has now evolved into an abundance of drugs and too few patients available to test them. Collaborative groups will aid in future efforts to find the best treatment strategies to improve the outcome for patients with PTCL.

Evolving Therapy of Peripheral T-cell Lymphoma: 2010 and beyond

The peripheral T-cell lymphomas are a rare, heterogeneous group of non-Hodgkin's lymphomas which have an aggressive clinical course. Treatment approaches have traditionally been similar to those of diffuse large B-cell lymphomas, but outcomes have been inferior. Novel approaches involving agents and pathways developed from a better understanding of the biology of the diseases have led to therapeutic advances. The introduction of new agents, including antifolates, immunoconjugates, histone deacetylase inhibitors, monoclonal antibodies, nucleoside analogs, proteasome inhibitors, and signaling inhibitors have improved outcomes for patients with relapsed and refractory disease and are being incorporated into strategies for first-line therapy. Stem cell transplantation remains a potentially curative option for a subset of patients.