title: Smoking is a risk factor for development of adult T-cell leukemia/lymphoma in Japanese human T-cell leukemia virus type-1 carriers.
abstract: Adult T-cell leukemia/lymphoma (ATLL) is an aggressive hematological malignancy caused by human T-cell leukemia virus type-1 (HTLV-1); no effective methods have yet been identified to prevent development of ATLL in carriers of HTLV-1. This study investigated the association between cigarette smoking and the risk of ATLL development among Japanese carriers of HTLV-1.
  
  
  
  This study examined the association between smoking and development of ATLL in a cohort of 1,332 Japanese HTLV-1 carriers aged 40-69 years free of ATLL at baseline from two different HTLV-1-endemic areas of Japan. Cox proportional hazards models adjusted for sex, geographic area, age at baseline, and alcohol drinking were used to estimate the effect of cigarette smoking on ATLL development.
  
  
  
  Between 1993 and 2012, 25 new ATLL cases were identified among these subjects. The overall crude incidence rate for ATLL was 1.08 per 1,000 person-years among HTLV-1 carriers and was higher among male carriers than among female carriers (2.21 vs. 0.74). The risk of ATLL development increased significantly with increasing numbers of cigarettes smoked per day (hazard ratio for every increment of 20 cigarettes, 2.03; 95 % confidence interval (CI) 1.13-3.66 overall, 2.07 (95 % CI 1.13-3.73) in male carriers).
  
  
  
  Cigarette smoking may influence ATLL development among HTLV-1 carriers in Japan.
authors.affiliation: Biostatistics Section, Division of Scientific Data Registry, Atomic Bomb Disease Institute, Nagasaki University, Sakamoto 1-12-4, Nagasaki, 852-8523, Japan. hkondo@nagasaki-u.ac.jp.
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Kondo
authors.affiliation: Department of Epidemiology, Radiation Effects Research Foundation, Nagasaki, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Soda
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Norie
authors.initials: N
authors.lastname: Sawada
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.|Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Manami
authors.initials: M
authors.lastname: Inoue
authors.affiliation: Department of Hematology, Nagasaki University Hospital, Nagasaki, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Imaizumi
authors.affiliation: Department of Hematology, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyazaki
authors.affiliation: Department of Frontier Life Science, Unit of Basic Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Iwanaga
authors.affiliation: Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D015368:Human T-lymphotropic virus 1; D006801:Humans; D007564:Japan; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects*
keywords: ATLL; Cigarette smoking; HTLV-1; Japanese