title: Case-control study on cigarette smoking and the risk of hepatocellular carcinoma among Japanese.
abstract: Emerging epidemiologic data suggest that cigarette smoking may increase the risk of hepatocellular carcinoma (HCC), yet considerable controversies (e.g. inconsistent dose-response relationships) still exist with this association. We examined whether smoking was associated with HCC risk in a case-control study including 209 incident HCC cases and two different control groups (256 hospital controls and 381 patients with chronic liver disease [CLD] without HCC). Comparison of HCC cases with CLD patients, but not with hospital controls, demonstrated a significantly increased risk of HCC for current smokers. After adjustment for sex, age, heavy drinking history and hepatitis virus markers, odds ratios (and 95% confidence intervals) for former and current smokers relative to never smokers were 1.0 (0.6-1.7) and 2.5 (1.4-4.6), respectively, against CLD patients, as compared with 0.8 (0.3-2.3) and 1.8 (0.6-5.1), respectively, against hospital controls. In terms of pack-years during lifetime, dose-response relationship was not evident against either control group (P trend = 0.43), but it became clearer for more recent cigarette use among CLD patients. For example, regarding cumulative cigarette consumption during the last 5 years, adjusted odds ratios (and 95% confidence intervals) for 1-4 and 5+ pack-years relative to no use were 1.9 (1.1-3.6) and 2.8 (1.5-5.2) (P trend = 0.003), respectively. These results suggest that cigarette smoking may play a crucial role in the late stage of HCC development and that CLD patients may benefit from their earliest smoking cessation.
authors.affiliation: Department of Preventive Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Hara
authors.forename: Keitaro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Higaki
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Mizuta
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Eguchi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yasutake
authors.forename: Iwata
authors.initials: I
authors.lastname: Ozaki
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Onohara
authors.forename: Seiji
authors.initials: S
authors.lastname: Kawazoe
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Shigematsu
authors.forename: Shunzo
authors.initials: S
authors.lastname: Koizumi
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008113:Liver Neoplasms / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*