Background: Chronic obstructive pulmonary disease (COPD) is associated with increased risk of lung cancer, independently of smoking. However, the relationship between COPD and total cancer mortality is less certain. We investigated the association between COPD and total cancer mortality and determined whether the use of statins, which have been associated with cancer risk in other settings, modified this relationship.
Methods: The study included 3371 patients with peripheral arterial disease who underwent vascular surgery between 1990 and 2006; 39% (n=1,310) with COPD and the rest without COPD. The primary endpoint was cancer mortality (lung and extra-pulmonary) over a median follow-up of 5 years.
Results: COPD was associated with increased risk of both lung cancer mortality (Hazard Ratio, HR 2.06; 95%CI 1.32-3.20) and extra-pulmonary cancer mortality (HR 1.43; 95%CI 1.06-1.94). The excess risk was mostly driven by patients with moderate and severe COPD. There was a trend towards lower cancer mortality risk among COPD patients who used statins compared to COPD patients without statins (HR 0.57; 95%CI 0.32-1.01). Interestingly, the risk of extra-pulmonary cancer mortality was lower among statin users with COPD (HR 0.49; 95% CI 0.24-0.99).
Conclusions: COPD was associated with increased lung and extra-pulmonary cancer mortality in this large cohort of vascular surgery patients with peripheral arterial disease. The risk of lung cancer mortality increased with progression of COPD. Statins were associated with reduced risk for extra-pulmonary cancer mortality in patients with COPD.