[The results of a nationwide survey on patients with adult T-cell leukemia-lymphoma].

Adult T-cell leukemia-lymphoma (ATL) is a rare disease, and the nationwide surveys conducted in Japan have played an important role in improving our understanding of the clinical features and prognosis of this disease. The diagnostic criteria of clinical subtypes have been proposed based on the surveys conducted on patients with ATL who were diagnosed in the 1980s; the current treatment guideline in Japan is based on this classification of ATL subtypes. In the survey for patients diagnosed between 2000 and 2009, the usefulness of the clinical subtypes was confirmed, and soluble interleukin-2 receptor was identified as a new prognostic factor for chronic- and smoldering-type ATL. We conducted another survey for patients who were diagnosed in 2010 and 2011. The age at diagnosis was higher than that reported in previous trials, and the median patient age at diagnosis was 68 years in the study. The 4-year survival rate was better than that in previous studies on acute- and lymphoma-type disease; however, the prognosis has not improved in chronic- and smoldering-type disease. Further nationwide surveys are expected to improve the treatment strategies for ATL.