PURPOSE: Tobacco smoke is a definite causative agent for lung cancer. It is increasingly being recognized that never-smokers can be afflicted with non-small-cell lung cancer (NSCLC). We aim to assess survival differences between smokers and never-smokers with NSCLC. PATIENTS AND METHODS: We analyzed 975 NSCLC patients who presented from January 1999 to December 2002. Clinical characteristics among current-, former- and never-smokers were tested using chi2 or Kruskal-Wallis test. The hazard ratio (HR) for death and its 95% CI were calculated by Cox regression. RESULTS: Of 975 patients, 59 had no smoking history and 33 had no quit time recorded. Of 883 patients analyzed, 286 patients (32.4%) were never-smokers. One hundred ninety-six never-smokers (68.5%) were females compared with 12% among current- and 13% among former-smokers (P < .001). There was a significant difference in histologic subtype between never-smokers and smokers: 69.9% with adenocarcinoma versus 39.9% (current-smokers) versus 47.3% (former-smokers); 5.9% with squamous cell carcinoma versus 35.7% (current-smokers) versus 28% (former-smokers; P < .001). Smokers had significantly poorer performance status (P = .002) and higher median age at diagnosis (P < .001) while more never-smokers presented with advanced disease (P = .002). Eight hundred and five patients (82.6%) died by May 30, 2005. The HR for smokers was significantly higher on both univariate and multivariate analysis (HR, 1.297; 95% CI, 1.040 to 1.619). CONCLUSION: Never-smokers comprised a high proportion of NSCLC patients in Singapore. Definite epidemiologic differences exist between never-smokers and smokers. Differences in survival outcome further suggest that the biology underlying the pathogenesis and behavior of the disease may be different for never-smokers.
PURPOSE:Tobacco smoke is a definite causative agent for lung cancer. It is increasingly being recognized that never-smokers can be afflicted with non-small-cell lung cancer (NSCLC). We aim to assess survival differences between smokers and never-smokers with NSCLC. PATIENTS AND METHODS: We analyzed 975 NSCLCpatients who presented from January 1999 to December 2002. Clinical characteristics among current-, former- and never-smokers were tested using chi2 or Kruskal-Wallis test. The hazard ratio (HR) for death and its 95% CI were calculated by Cox regression. RESULTS: Of 975 patients, 59 had no smoking history and 33 had no quit time recorded. Of 883 patients analyzed, 286 patients (32.4%) were never-smokers. One hundred ninety-six never-smokers (68.5%) were females compared with 12% among current- and 13% among former-smokers (P < .001). There was a significant difference in histologic subtype between never-smokers and smokers: 69.9% with adenocarcinoma versus 39.9% (current-smokers) versus 47.3% (former-smokers); 5.9% with squamous cell carcinoma versus 35.7% (current-smokers) versus 28% (former-smokers; P < .001). Smokers had significantly poorer performance status (P = .002) and higher median age at diagnosis (P < .001) while more never-smokers presented with advanced disease (P = .002). Eight hundred and five patients (82.6%) died by May 30, 2005. The HR for smokers was significantly higher on both univariate and multivariate analysis (HR, 1.297; 95% CI, 1.040 to 1.619). CONCLUSION: Never-smokers comprised a high proportion of NSCLCpatients in Singapore. Definite epidemiologic differences exist between never-smokers and smokers. Differences in survival outcome further suggest that the biology underlying the pathogenesis and behavior of the disease may be different for never-smokers.
Authors: Linda Kachuri; Christopher I Amos; James D McKay; Mattias Johansson; Paolo Vineis; H Bas Bueno-de-Mesquita; Marie-Christine Boutron-Ruault; Mikael Johansson; J Ramón Quirós; Sabina Sieri; Ruth C Travis; Elisabete Weiderpass; Loic Le Marchand; Brian E Henderson; Lynne Wilkens; Gary E Goodman; Chu Chen; Jennifer A Doherty; David C Christiani; Yongyue Wei; Li Su; Shelley Tworoger; Xuehong Zhang; Peter Kraft; David Zaridze; John K Field; Michael W Marcus; Michael P A Davies; Russell Hyde; Neil E Caporaso; Maria Teresa Landi; Gianluca Severi; Graham G Giles; Geoffrey Liu; John R McLaughlin; Yafang Li; Xiangjun Xiao; Gord Fehringer; Xuchen Zong; Robert E Denroche; Philip C Zuzarte; John D McPherson; Paul Brennan; Rayjean J Hung Journal: Carcinogenesis Date: 2015-11-20 Impact factor: 4.944