Epidemiology of adult T-cell leukemia-lymphoma in Japan: an updated analysis, 2012-2013.

Adult T-cell leukemia-lymphoma (ATL) is a T-cell malignancy that is endemic to Japan. In this latest nationwide study of ATL, we collected data of patients diagnosed in 2012-2013 from four nationwide registries; the Hematology Blood Disease, the Skin Cancer Society, the Hospital-Based Cancer Registries, and information from the hospitals that participated in the Japanese nationwide survey of ATL in 2010-2011. In the present study, 2,614 patients with ATL were diagnosed according to the registries, and 117 departments registered 1,042 patients. Among these patients, 984 were eligible for analysis. The median age at diagnosis was 69 years. A larger proportion of patients with ATL older than 70 years were diagnosed with the lymphoma subtype, and more than half of patients with ATL in the metropolitan areas were born in the human T-cell leukemia virus type I (HTLV-1)-endemic areas of Kyushu/Okinawa, which are almost identical to the findings in our 2010-2011 study. Additionally, we identified that patients with ATL migrated from the endemic areas for HTLV-1 to the non-endemic metropolitan areas. The present study was able to reduce the burden of searching each hospital and to update the clinico-epidemiological characteristics of a large number of patients with ATL in Japan, suggesting the usefulness and feasibility of the novel data collection method. The establishment of a more sophisticated database management system for ATL is necessary for future continuous surveys. This article is protected by copyright. All rights reserved.