Abstract
Objective: To examine whether emphysema and airway wall thickness are risk factors to incidence of pulmonary cancer, independent of current smoking status, pack years, gender and age in subjects with and without COPD.
Methods: We used data from a cohort of 947 ever-smokers, aged 40-75 years, (49% with COPD), examined in 2003/04. The examination included CT thorax, lung function measurements and questionnaires on smoking history. These data were merged with data from the Norwegian Cancer Register in a follow-up study over 8 years.
Results: Altogether 29 subjects were diagnosed with pulmonary cancer during the follow-up period (27 among the COPD patients and 2 among those without COPD). The median (25/75percentiles) level of emphysema in those diagnosed with pulmonary cancer was 16.65% (4.64/22.33) and 1.41 (0.40/6.07) in those not diagnosed with pulmonary cancer. Mean (SD) airway wall thickness (AWT) in those with and without pulmonary cancer were 0.48 (0.03) and 0.49 (0.03). The hazard ratio for being diagnosed with pulmonary cancer was 1.06 (95%CI: 1.03-1.09) per percentage points increase in level of emphysema after adjusting for gender, age, smoking and pack years. There was no emphysemaXpackyears interaction in risk of pulmonary cancer. AWT did not predict pulmonary cancer independently.
Conclusion: Level of emphysema was an independent risk factor to incidence of pulmonary cancer while airway wall thickness was not.
- © 2014 ERS