Striving to cure adult T-cell leukaemia/lymphoma: a role for allogeneic stem cell transplant?

Clinical and Public Health Implications of Human T-Lymphotropic Virus Type 1 Infection

Human T-lymphotropic virus type 1 (HTLV-1) is estimated to affect 5 to 10 million people globally and can cause severe and potentially fatal disease, including adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The burden of HTLV-1 infection appears to be geographically concentrated, with high prevalence in discrete regions and populations. While most high-income countries have introduced HTLV-1 screening of blood donations, few other public health measures have been implemented to prevent infection or its consequences. Recent advocacy from concerned researchers, clinicians, and community members has emphasized the potential for improved prevention and management of HTLV-1 infection. Despite all that has been learned in the 4 decades following the discovery of HTLV-1, gaps in knowledge across clinical and public health aspects persist, impeding optimal control and prevention, as well as the development of policies and guidelines. Awareness of HTLV-1 among health care providers, communities, and affected individuals remains limited, even in countries of endemicity. This review provides a comprehensive overview on HTLV-1 epidemiology and on clinical and public health and highlights key areas for further research and collaboration to advance the health of people with and at risk of HTLV-1 infection.

Increased incidence of adult T cell leukemia-lymphoma and peripheral T cell lymphoma-not otherwise specified with limited improvement in overall survival: a retrospective analysis using data from the population-based Osaka Cancer Registry

Peripheral T cell lymphomas (PTCL) are a heterogeneous group of non-Hodgkin lymphomas with poor outcomes. Adult T cell leukemia-lymphoma (ATL) and PTCL-not otherwise specified (PTCL-NOS)-are 2 common mature T cell lymphomas in Japan. Since it is unclear whether novel agents and treatment strategies incorporating hematopoietic cell transplantation have contributed to improved clinical outcomes in the real world, we performed a retrospective analysis using data from the population-based Osaka Cancer Registry. From 1977 to 2014, 1274 and 1143 patients were diagnosed with ATL or PTCL-NOS, respectively. Recently, the incidence of both diseases has gradually increased, and the age at diagnosis has risen. The 3-year overall survival (OS) rates in ATL patients were 12.0% in era 1 (1977-1999), 12.4% in era 2 (2000-2008), and 17.5% in era 3 (2009-2014) (P < 0.001). The 3-year OS rates in PTCL-NOS patients were 27.6% in era 1, 36.2% in era 2, and 35.0% in era 3 (P = 0.049). In conclusion, the incidences of ATL and PTCL-NOS have been increasing, particularly in elderly individuals. Clinical outcomes have improved in recent decades but are still unsatisfactory in both diseases. Thus, effective new treatment strategies incorporating novel agents are needed to further improve clinical outcomes in patients with ATL and PTCL-NOS.

Resolution of bone, cutaneous, and muscular involvement after haploidentical hematopoietic stem cell transplantation followed by post-transplant cyclophosphamide in adult T-cell leukemia/lymphoma

Haploidentical hematopoietic stem cell transplantation followed by post-transplant cyclophosphamide provides a well-tolerated and potentially curable treatment for chemorefractory acute-type adult T-cell leukemia/lymphoma.

Allogeneic Stem Cell Transplantation for Adult T-Cell Leukemia/Lymphoma-Romanian Experience

Adult T-cell leukemia/lymphoma (ATLL) is a rare and aggressive mature T-cell malignancy caused by the human T lymphoma virus I (HTLV-I) affecting 3–5% of HTLV-1 carriers and is usually diagnosed in endemic regions. Romania is a region with high prevalence of HTLV-1 infection and ATLL and with low median age at diagnosis for aggressive types. We performed a retrospective analysis of post-transplant outcome in the first Romanian patients with ATLL receiving hematopoietic stem cell allotransplant. The study population included eight patients (three males, five females), with median age of 39.5 (range 26–57), with acute (one case) and lymphoma type (seven cases) that received peripheral stem cells (PBSC) from matched related (MRD) and unrelated donors (MUD) after reduced intensity conditioning. Graft versus host disease (GVHD) developed in six patients. Relapse occurred in four cases (50%) at a median time of 5-months post-transplant. Six patients died: four cases with disease-related deaths and two patients with GVHD-related deaths. The median survival post-transplant was 19.5 months (range 2.3–44.2 months). The post-transplant survival at 1-year was 62.5%, at 2-years 50%, and at 3-years 37.5%. In our opinion allogeneic transplant improves outcome in aggressive type ATLL.

Updates in lymph node and skin pathology of adult T-cell leukemia/lymphoma, biomarkers, and beyond

Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell lymphoproliferative disorder associated with the human T lymphotropic virus (HTLV-1) infection. ATLL predominantly affects individuals within HTLV-1 endemic areas such as Japan, areas of Africa, South America, and the Caribbean. HTLV-1 preferentially infects CD4+ T-cells, and several genetic hits must occur before ATLL develops. ATLL is classically divided into four clinical variants based on manifestations of disease: acute, chronic, lymphomatous, and smouldering. As of 2019, a new subtype has been described: lymphoma type of ATL, extranodal primary cutaneous. In this review, emphasis will be taken to describe the common clinicopathologic manifestations of the disease, advances in biomarker discovery, mutational landscape and targeted therapeutic approaches to treat this highly aggressive and frequently lethal type of T-cell lymphoma.

Barriers to Allogeneic Hematopoietic Stem Cell Transplantation for Human T Cell Lymphotropic Virus 1-Associated Adult T Cell Lymphoma-Leukemia in the United States: Experience from a Large Cohort in a Major Tertiary Center

In the United States adult T cell lymphoma-leukemia (ATLL) carries a dismal prognosis and mainly affects immigrants from human T cell lymphotropic virus 1 endemic areas. Allogeneic hematopoietic stem cell transplant (alloHSCT) can be effective and is recommended as an upfront treatment in the National Comprehensive Cancer Network guidelines. We studied the barriers to alloHSCT in one of the largest ATLL populations in the United States. Comprehensive chart and donor registry reviews were conducted for 88 ATLL patients treated at Montefiore Medical Center from 2003 to 2018. Among 49 patients with acute and 32 with lymphomatous subtypes, 48 (59.5%) were ineligible for alloHSCT because of early mortality (52%), loss to follow-up (21%), uninsured status (15%), patient declination (10%), and frailty (2%). Among 28 HLA-typed eligible patients (34.6%), matched related donors were identified for 7 (25%). A matched unrelated donor (MUD) search yielded HLA-matched in 2 patients (9.5%), HLA mismatched in 6 (28.5%), and no options in 13 (62%). Haploidentical donors were identified for 6 patients (46%) with no unrelated options. There were no suitable donors for 7 (25%) alloHSCT-eligible patients. The main limitation for alloHSCT after donor identification was death from progressive disease (82%). AlloHSCT was performed in 10 patients (12.3%) and was associated with better relapse-free survival (26 versus 11 months, P = .04) and overall survival (47 versus 10 months, P = .03). Early mortality and progressive disease are the main barriers to alloHSCT, but poor follow-up, uninsured status, and lack of suitable donor, including haploidentical, are also substantial limitations that might disproportionally affect this vulnerable population. AlloHSCT can achieve long-term remissions, and strategies aiming to overcome these barriers are urgently needed to improve outcomes in ATLL.

A retrospective analysis of haplo-identical HLA-mismatch hematopoietic transplantation without posttransplantation cyclophosphamide for GVHD prophylaxis in patients with adult T-cell leukemia-lymphoma

Currently, allogeneic hematopoietic stem cell transplantation (allo-HCT) is the only available curative modality for patients with adult T-cell leukemia-lymphoma (ATL). When used in conjunction with posttransplantation cyclophosphamide (PTCY) for graft-versus-host disease prophylaxis, allo-HCT from an HLA haplo-identical donor yields promising outcomes for many diseases other than ATL. However, appropriate comparisons with other donor sources, especially cord blood and conventional HLA haplo-identical donors, are needed to validate the safety and efficacy of this modality. In this study, we retrospectively evaluated the outcome of allo-HCT without PTCY in patients with ATL registered in the Japan Society for Hematopoietic Cell Transplantation TRUMP database between 1985 and 2015. During that period, 46 patients received allo-HCT without PTCY and survivors were followed for a median of 2316.5 days (range: 220-3884 days). Although the estimated 1- and 5-year overall survival rates of the entire cohort were 34.5% and 17.7%, respectively, the cumulative 1- and 5-year non-ATL mortality rates of 41.3% and 55.8%, respectively, were high. The results of our study will serve as a platform for discussions of the safety and efficacy of haplo-HCT for future clinical trials in patients with ATL.

A Review of New Findings in Adult T-cell Leukemia-Lymphoma: A Focus on Current and Emerging Treatment Strategies

Adult T-cell leukemia–lymphoma (ATL), a rare and aggressive T-cell malignancy caused by human T-cell lymphotropic virus type 1 (HTLV-1), is associated with a poor prognosis. Evidence-based standard treatment options are lacking and outcomes are generally unsatisfactory, particularly for patients with relapsed or refractory disease. Continued research is contributing to changing treatment landscape as a number of existing and investigational agents are evaluated. We describe the epidemiology of HTLV-1 and ATL, discuss the biology behind the disease, review current treatment practices and guidelines, and provide an overview of emerging therapies in ATL, with a focus on those for relapsed or refractory disease.

Human T Cell Leukemia Virus Type 1: Persistence and Pathogenesis

Human T cell leukemia virus type 1 (HTLV-1), also known as human T lymphotropic virus type 1, was the first exogenous human retrovirus discovered. Unlike the distantly related lentivirus HIV-1, HTLV-1 causes disease in only 5-10% of infected people, depending on their ethnic origin. But whereas HIV-1 infection and the consequent diseases can be efficiently contained in most cases by antiretroviral drug treatment, there is no satisfactory treatment for the malignant or inflammatory diseases caused by HTLV-1. The purpose of the present article is to review recent advances in the understanding of the mechanisms by which the virus persists in vivo and causes disabling or fatal diseases.

Development of a modified prognostic index for patients with aggressive adult T-cell leukemia-lymphoma aged 70 years or younger: possible risk-adapted management strategies including allogeneic transplantation

Adult T-cell leukemia-lymphoma is a distinct type of peripheral T-cell lymphoma caused by human T-cell lymphotropic virus type I. Although allogeneic stem cell transplantation after chemotherapy is a recommended treatment option for patients with aggressive adult T-cell leukemia-lymphoma, there is no consensus about indications for allogeneic stem cell transplantation because there is no established risk stratification system for transplant eligible patients. We conducted a nationwide survey of patients with aggressive adult T-cell leukemia-lymphoma in order to construct a new, large database that includes 1,792 patients aged 70 years or younger with aggressive adult T-cell leukemia-lymphoma who were diagnosed between 2000 and 2013 and received intensive first-line chemotherapy. We randomly divided patients into two groups (training and validation sets). Acute type, poor performance status, high soluble interleukin-2 receptor levels (> 5,000 U/mL), high adjusted calcium levels (≥ 12 mg/dL), and high C-reactive protein levels (≥ 2.5 mg/dL) were independent adverse prognostic factors used in the training set. We used these five variables to divide patients into three risk groups. In the validation set, median overall survival for the low-, intermediate-, and high-risk groups was 626 days, 322 days, and 197 days, respectively. In the intermediate- and high-risk groups, transplanted recipients had significantly better overall survival than non-transplanted patients. We developed a promising new risk stratification system to identify patients aged 70 years or younger with aggressive adult T-cell leukemia-lymphoma who may benefit from upfront allogeneic stem cell transplantation. Prospective studies are warranted to confirm the benefit of this treatment strategy.