title: Hazard Ratio of Smoking on Lung Cancer in Korea According to Histological Type and Gender.
abstract: OBJECTIVE
  Using nationwide cancer incidence data, we examined whether the strength of the association of cigarette smoking with lung cancer risk differs according to major histological type and gender, taking account of other risk factors in the Korean population.
  
  
  METHODS
  The study population derived from government employees and teachers aged 20 years and over who participated in a national health examination program in 1998 or 1999. Total study subjects were 1,357,447. After excluding 1556 subjects who were treated with lung cancer during 1998-2000, we restricted our analysis to 1,355,891 cases. We followed up those 1,355,891 subjects who were cancer-free at baseline until December 31, 2010. The incident cancer cases were identified from the Korea Central Cancer Registry, which is a nationwide hospital-based cancer registry system that includes 94 % of the university hospitals and 96 % of the resident training hospitals of the country.
  
  
  RESULTS
  A higher risk for having ever smoked was observed for squamous-cell and small-cell carcinoma in both men and women. Heavy and long-term smokers were at higher risk for these carcinomas. Significant associations with quantity and duration-related factors were observed mainly among men. These findings indicate that smoking is closely related to the risk of squamous-cell and small-cell carcinoma among women as well as men. However, the magnitude of smoking-related lung cancer risk is likely to differ between men and women.
  
  
  CONCLUSIONS
  The hazard ratios for all types of lung cancer were significantly higher in male current smokers than in male never smokers. In case of women, the hazard ratios for adenocarcinoma were not different between current smokers and never smokers. The hazard ratios we found, however, were lower than those reported in Western countries and in Korea, but consistent with those reported in North-eastern Asian countries.
authors.affiliation: Health Insurance Policy Research Institute, National Health Insurance Service, Seoul, Republic of Korea.
authors.forename: Young Duk
authors.initials: YD
authors.lastname: Yun
authors.affiliation: Health Insurance Policy Research Institute, National Health Insurance Service, Seoul, Republic of Korea.
authors.forename: Joung Hwan
authors.initials: JH
authors.lastname: Back
authors.affiliation: Health Insurance Policy Research Institute, National Health Insurance Service, Seoul, Republic of Korea.
authors.forename: Haryeom
authors.initials: H
authors.lastname: Ghang
authors.affiliation: Department of Epidemiology and Health Promotion, Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Republic of Korea.
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Jee
authors.affiliation: National Cancer Control Institute, National Cancer Center, Goyang, Gyeonggi-do, Republic of Korea.
authors.forename: Yeol
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Health Insurance Policy Research Institute, National Health Insurance Service, Seoul, Republic of Korea.
authors.forename: Sun Mi
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, and Institute for Global Health, University of Southern California, Los Angeles, CA, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Samet
authors.affiliation: Department of Psychiatry, CHA Bundang Medical Center, CHA University, 59 Yatap-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-712, Republic of Korea. kpsimon@hanmail.net.
authors.forename: Kang Soo
authors.identifier: http://orcid.org/0000-0001-6587-5623
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D000328:Adult; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012042:Registries; D056910:Republic of Korea / Q000453:epidemiology; D018570:Risk Assessment; D012307:Risk Factors; D017678:Sex Distribution; D012737:Sex Factors; D055752:Small Cell Lung Carcinoma / Q000453:epidemiology / Q000473:pathology; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology*; D013997:Time Factors; D055815:Young Adult
keywords: Cigarette; Gender; Histologic type; Lung cancer; Smoking