Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoproliferative disorders arising from mature T cells, accounting for about 10% of non-Hodgkin lymphomas. PTCL-not otherwise specified is the most common subtype, followed by angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma, anaplastic lymphoma kinase–positive, anaplastic large cell lymphoma, anaplastic lymphoma kinase–negative, and enteropathy-associated T-cell lymphoma. This discussion section focuses on the diagnosis and treatment of PTCLs as outlined in the NCCN Guidelines for T-Cell Lymphomas.
Peripheral T-cell lymphomas (PTCLs) represent a relatively uncommon heterogeneous group of non-Hodgkin's lymphomas (NHLs) with an aggressive clinical course and poor prognosis. Anthracycline-based multiagent chemotherapy with or without radiation therapy followed by first-line consolidation with high-dose therapy followed by autologous stem cell rescue (HDT/ASCR) is the standard approach to most of the patients with newly diagnosed PTCL. Relapsed or refractory disease is managed with second-line systemic therapy followed by HDT/ASCR or allogeneic stem cell transplant, based on the patient's eligibility for transplant. In recent years, several newer agents have shown significant activity in patients with relapsed or refractory disease across all 4 subtypes of PTCL. These NCCN Guideline Insights highlight the important updates to the NCCN Guidelines for NHL, specific to the management of patients with relapsed or refractory PTCL.
Diffuse large B-cell lymphomas (DLBCL) are now considered a heterogeneous group of distinct molecular subtypes (germinal center B-cell DLBCL, activated B-cell DLBCL, and primary mediastinal large B-cell lymphoma (PMBL) with varied natural history and response to therapy. In addition, a subset of patients with DLBCL have concurrent MYC and/or BCL2 gene rearrangements (double-hit lymphomas; DHL) and others have a dual expression of both MYC and BCL2 proteins (double-expressing DLBCL; DEL). The standard of care for the treatment of patients with PMBL, DHL, or DEL has not been established. Adequate immunophenotyping and molecular testing (in selected circumstances) are necessary for the accurate diagnosis of different subtypes of DLBCL. The NCCN Guidelines included in this issue, part of the NCCN Guidelines for non-Hodgkin's lymphomas, address the diagnosis and management of DLBCL and its subtypes.
Overview Mycosis fungoides/Sézary syndrome (MF/SS) is the most common cutaneous T‐cell lymphoma. It originates in the skin and its presentation may range from very limited patch disease to wide‐spread cutaneous tumors. When there is peripheral blood involvement, usually in conjunction with erythroderma, it is known as the SS. Although patients with limited patch disease have a very long natural history, respond to a variety of topical therapies, and even enjoy a survival similar to age‐matched control populations, patients who present with cutaneous tumors or extracutaneous disease have a relentless progressive course of disease. Treatments for patients with limited disease are primarily topical and include topical chemotherapy (nitrogen mustard), radiation therapy, and phototherapy. When the disease is advanced, topical therapies are still often needed, but systemic treatment becomes essential. Conventional chemotherapy (single agent or combination) is often not effective. However, systemic biologics such as histone deacetylase inhibitors, the interferons, photopheresis, alemtuzumab, and brentuximab vedotin may achieve responses. Most recently, hematopoietic cell transplant, especially with nonablative conditioning regimens, has shown promising results in a cohort of patients with advanced MF or SS.
