Adult T-cell Leukemia/Lymphoma (ATL) in Japan

• Published in: Journal of Epidemiology Vol. 2; no. 2sup; pp. 63 - 74
• Main Author: Tajima, Kazuo
• Format: Journal Article
• Language: English
• Published: Japan Epidemiological Association 1992
• Subjects: Adult T-cell leukemiaAymphoma; Human T-cell leukemia virus type l; Prevention trial
• ISSN: 0917-5040; 1349-9092
• DOI: 10.2188/jea.2.2sup_63

A specific type of lymphoid malignancy, adult T-cell leukemia/ lymphoma(ATL), which is caused by human T-cell leukemia virus type I (HTLV-I), is highly prevalent and there are also many healthy carriers of HTLV-I in the same areas. Three main routes of HTLV-I transmission are recognized: 1) vertical transmission from mother to child mainly through breast milk, 2) horizontal transmission from man to woman through semen, and, 3) parenteral transmission from carrier donor to non-carrier recipient. The annual incidence rate of ATL among HTLV-I carriers is estimated at 2.0 in males and 0.5 in females, and the cumulative risk for ATL in HTLV-I carriers during a 70-year life span is 2-5%. Possible risk factors for ATL in addition to HTLV-Iinfection were considered, i.e. genetic factors, environmental factors, nutritional condition, thymus involution and so on. ATL in Japan is an important subject for study in the field of cancer epidemiology, and several trial intervention programs for the prevention of ATL, such as controls of vertical transmission from mother to child through breast milk, are now in progress in ATL-endemic areas in Japan.