Epidemiological and clinical features of adult T‐cell leukemia–lymphoma in Japan, 2010–2011: A nationwide survey

Abstract

Adult T‐cell leukemia–lymphoma (ATL) is a mature T‐cell malignancy associated with human T‐cell leukemia virus type 1 (HTLV‐1) infection. Japan is the most endemic country for HTLV‐1 and ATL in the world. Recent nationwide studies of Japanese blood donors reported that HTLV‐1 carriers spread from endemic areas to non‐endemic areas. Therefore, the latest information on nationwide epidemiological and clinical data for ATL is necessary to guide clinical practice. We undertook a multicenter, hospital‐based survey of newly diagnosed ATL patients from 2010 to 2011. A total of 996 patients with ATL were registered from 126 hospitals across Japan. Of those, 922 (487 men and 435 women) were included in the analysis. The median age at diagnosis was 68 years (interquartile range, 60–75 years). Overall, 67.2% of ATL was diagnosed in the Kyushu–Okinawa area. The most common subtype was acute (49.5%), followed by lymphoma (25.7%), chronic (14.2%), and smoldering (10.6%). Lymphoma type was more prevalent in men (60%), whereas chronic was more prevalent in women (60%). Half of patients with lymphoma type were aged over 70 years, whereas one‐third of patients with the chronic type were aged under 60 years. All of these characteristics were different from those of the previous nationwide surveys in the 1980s and 1990s. This survey clarified that half of current patients with ATL are aged over 68 years who were unable to receive intensive cytotoxic therapies. New less toxic agents for aged patients and further strategies to prevent the development of ATL from HTLV‐1 carrier status are needed.

Epidemiology and survival trend of adult T‐cell leukemia/lymphoma in the United States

“…We did not observe any sex difference in ATLL incidence, and this is similar to the report from Japan (Table ). As expected, our analysis revealed a distinct geographic distribution, with 30% of ATLL cases diagnosed in the states of New York and Florida (Fig.…”

“…The median age at diagnosis in the United States was 62 years in the SEER18 data and 59 years in NYSCR. In Japan, the median age at diagnosis is 68 years, which is almost a decade later than the median age in the United States . The lower median age at diagnosis in the United States, especially in NHBs, in comparison with the Japanese needs further study.…”

New Therapies and Immunological Findings in Cutaneous T-Cell Lymphoma

“…Cutaneous involvement is frequently observed in patients with ATL at 30–70% ( 160 , 161 ), regardless of ATL subtype. Cutaneous manifestation in the smoldering type of ATL has been suggested to reflect poor prognosis ( 162 ), and cutaneous ATL was recently proposed to include the lymphoma type as an extranodal variant ( 163 ).…”

Mouse Models That Enhanced Our Understanding of Adult T Cell Leukemia

“…Approximately 5–20 million people are infected with HTLV-I worldwide (reviewed in Gessain and Cassar, 2012 ). However, the highest prevalence is reported in endemic areas that include Japan, the Caribbean, South America, inter-tropical Africa, Pacific islands, some areas in the Middle East, and Romania ( Nosaka et al, 2017 , reviewed in Edlich et al, 2003 ; Gessain and Cassar, 2012 ). The genome of this virus encodes for classical structural proteins required for retroviral replication and a series of accessory and regulatory proteins including the viral transcriptional activator Tax ( Lee et al, 1984 , reviewed in Azran et al, 2004 ) and the HTLV-I bZIP factor gene (HBZ), a viral protein encoded from the 3′ long terminal repeat (LTR) in the complementary strand of the proviral genome ( Gaudray et al, 2002 , reviewed in Matsuoka and Jeang, 2011 ; Giam and Semmes, 2016 ; Ma et al, 2016 ).…”