Adult T Cell Leukemia-Lymphoma (ATL): State of the Art

ATL is a rare and highly aggressive T cell malignancy caused by HTLV-1. We will review the state of the art of ATL epidemiology, pathogenesis, diagnosis, and treatment. Because of population migration, cases of ATL in non-HTLV-1 endemic countries including North America and Europe are increasingly recognized. ATL has diverse clinical manifestations, limited treatment options not widely available globally, and poor prognosis despite therapy. A small subset of patients may achieve prolonged survival with antiviral therapy or allogeneic stem cell transplant. Mogamulizumab, an anti-CCR4 monoclonal antibody, and lenalidomide, an immunomodulatory drug, are approved for ATL in Japan. Molecular studies have identified key alterations in T cell signaling and DNA methylation that may further guide drug development. Patients should be encouraged to enroll in prospective clinical trials when possible. Ongoing, collaborative, international research continues to elucidate disease pathogenesis and contribute to an evolving therapeutic landscape for ATL.