Guidelines for the management of mature T‐cell and NK‐cell neoplasms (excluding cutaneous T‐cell lymphoma)

Abstract

SummaryThe peripheral T-cell neoplasms are a biologically and clinically heterogeneous group of rare disorders that result from clonal proliferation of mature post-thymic lymphocytes. Natural killer (NK) cell neoplasms are included in this group. The World Health Organization classification of haemopoietic malignancies has divided this group of disorders into those with predominantly leukaemic (disseminated), nodal, extranodal or cutaneous presentation. They usually affect adults and are more commonly reported in males than in females. The median age at diagnosis is 61 years with a range of 17-90 years. Although some subtypes may follow a relatively benign protracted course most have an aggressive clinical behaviour and poor prognosis. Excluding anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL), which has a good outcome, 5-year survival for other nodal and extranodal T-cell lymphomas is about 30%. Most patients present with unfavourable international prognostic index scores (>3) and poor performance status. The rarity of these diseases and the lack of randomized trials mean that there is no consensus about optimal therapy for T-and NK-cell neoplasms and recommendations in this guideline are therefore based on small case series, phase II trials and expert opinion.

Cutaneous Manifestations of Unspecified Peripheral T-Cell Lymphoma May Be Indicative of Disease Activity and Predict Response to Therapy

“…These lymphomas demonstrate poorresponsetoconventionaltherapiessuchascyclophosphamide,doxorubicin,vincristine,andprednisone, although this regimen anachronistically remains first-line therapy despite never having been established as the preferred or most effective treatment for ALK-negative PTCL. 3,4 Five-year survival rates for T-cell lymphoma that is treated with regimens like cyclophosphamide, doxorubicin, vincristine, and prednisone remains in the 20% to 35% range, and are below reported response rates in similarly aggressive B-cell lymphoma counterparts. 5 Recent clinical practice has expanded the use of new and experimental treatments in clinical trials.…”

“…Evidence-based recommendations in fact advocate the use of experimental agents in controlled settings. 4 Romidepsin belongs to an epigenetic regulator class of drugs known as histone deacetylase inhibitors. The response of PTCL to romidepsin was documented in a case report in 2001.…”

A phase 2 study of methotrexate, etoposide, dexamethasone, and pegaspargase chemotherapy for newly diagnosed, relapsed, or refractory extranodal natural killer/T‐cell lymphoma, nasal type: a multicenter trial in Northwest China

“…Historically, the poor outcome and high incidence of resistance to conventional therapy may be associated with overexpression of P‐glycoprotein, a transmembrane pump that transports anthracycline‐based chemotherapeutics and results in multidrug resistance 11, 12, 13, 14, 15. Given this complication, optimal treatment strategies for patients with NKTCL have not been determined, and studies have focused on improving the efficacy of chemotherapy and reducing the risk of disease recurrence 16, 17, 18…”

An unusual extranodal T-cell non-Hodgkin lymphoma

“…5 In our patient presenting with myositis, the diagnosis was additionally confounded by the anatomical restriction of non Hodgkin lymphoma (NHL) exclusively to the bone marrow, with no detectable disease at nodal or other extra-nodal sites even with sensitive PET/CT imaging. Thus, while bone marrow examination in nodal highgrade NHL is generally of prognostic, but not diagnostic utility, 4 in our patient, the trephine biopsy proved to be most useful for the diagnosis. Through this report, we intend to increase awareness of the unique disease-distribution and clinical features of rarer primary extra-nodal NHL that could result in diagnostic delay despite a concerted multi-disciplinary approach.…”

“…4 In contrast, myositis, through unknown mechanisms is a rarer paraneoplastic occurrence with the potential to complicate the diagnostic process. 5 In our patient presenting with myositis, the diagnosis was additionally confounded by the anatomical restriction of non Hodgkin lymphoma (NHL) exclusively to the bone marrow, with no detectable disease at nodal or other extra-nodal sites even with sensitive PET/CT imaging.…”