INTRODUCTION: The majority of cases of both lung cancer and chronic obstructive pulmonary disease (COPD) are attributable to cigarette smoking, but whether COPD is an independent risk factor for lung cancer remains unclear. METHODS: We used The Health Improvement Network, a U.K. general practice database, to identify incident cases of lung cancer and controls matched on age, sex, and practice. Using conditional logistic regression, we assessed the effects of timing of first diagnoses of COPD, pneumonia, and asthma on the odds of lung cancer, adjusting for smoking habit. RESULTS: Of 11,888 incident cases of lung cancer, 23% had a prior diagnosis of COPD compared with only 6% of the 37,605 controls. The odds of lung cancer in patients who had COPD diagnosed within 6 months of their cancer diagnosis were 11-fold those of patients without COPD (odds ratio 11.47, 95% confidence interval 9.38-14.02). However, when restricted to earlier COPD diagnoses, with adjustment for smoking, the effect markedly diminished (for COPD diagnoses >10 years before lung cancer diagnosis, odds ratio: 2.18, 95% confidence interval: 1.87-2.54). The pattern was similar for pneumonia. The effect of COPD on lung cancer remained after excluding patients who had a codiagnosis of asthma. CONCLUSION: A diagnosis of COPD is strongly associated with a diagnosis of lung cancer, however, this association is largely explained by smoking habit, strongly dependent on the timing of COPD diagnosis, and not specific to COPD. It seems unlikely, therefore, that COPD is an independent risk factor for lung cancer.
INTRODUCTION: The majority of cases of both lung cancer and chronic obstructive pulmonary disease (COPD) are attributable to cigarette smoking, but whether COPD is an independent risk factor for lung cancer remains unclear. METHODS: We used The Health Improvement Network, a U.K. general practice database, to identify incident cases of lung cancer and controls matched on age, sex, and practice. Using conditional logistic regression, we assessed the effects of timing of first diagnoses of COPD, pneumonia, and asthma on the odds of lung cancer, adjusting for smoking habit. RESULTS: Of 11,888 incident cases of lung cancer, 23% had a prior diagnosis of COPD compared with only 6% of the 37,605 controls. The odds of lung cancer in patients who had COPD diagnosed within 6 months of their cancer diagnosis were 11-fold those of patients without COPD (odds ratio 11.47, 95% confidence interval 9.38-14.02). However, when restricted to earlier COPD diagnoses, with adjustment for smoking, the effect markedly diminished (for COPD diagnoses >10 years before lung cancer diagnosis, odds ratio: 2.18, 95% confidence interval: 1.87-2.54). The pattern was similar for pneumonia. The effect of COPD on lung cancer remained after excluding patients who had a codiagnosis of asthma. CONCLUSION: A diagnosis of COPD is strongly associated with a diagnosis of lung cancer, however, this association is largely explained by smoking habit, strongly dependent on the timing of COPD diagnosis, and not specific to COPD. It seems unlikely, therefore, that COPD is an independent risk factor for lung cancer.
Authors: Jens Köhler; Martin Schuler; Thomas Christoph Gauler; Stefanie Nöpel-Dünnebacke; Maike Ahrens; Andreas-Claudius Hoffmann; Stefan Kasper; Felix Nensa; Benedikt Gomez; Maria Hahnemann; Frank Breitenbuecher; Danjouma Cheufou; Filiz Özkan; Kaid Darwiche; Mathias Hoiczyk; Henning Reis; Stefan Welter; Wilfried Ernst Erich Eberhardt; Martin Eisenacher; Helmut Teschler; Georgios Stamatis; Wolff Schmiegel; Stephan Albrecht Hahn; Alexander Baraniskin Journal: J Cancer Res Clin Oncol Date: 2015-12-19 Impact factor: 4.553
Authors: Melissa J McDonnell; Stefano Aliberti; Pieter C Goeminne; Marcos I Restrepo; Simon Finch; Alberto Pesci; Lieven J Dupont; Thomas C Fardon; Robert Wilson; Michael R Loebinger; Dusan Skrbic; Dusanka Obradovic; Anthony De Soyza; Chris Ward; John G Laffey; Robert M Rutherford; James D Chalmers Journal: Lancet Respir Med Date: 2016-11-16 Impact factor: 30.700