COPD linked to increased lung cancer risk in nonsmokers
Among people who have never smoked, the risk for lung cancer was more than twice as high among those with COPD, as compared with those without COPD, according to a Korean study.
The risk for lung cancer among study participants with COPD who never smoked was also comparable to that of participants who had smoked but did not have COPD. Specifically, when compared with participants who never smoked and did not have COPD, the adjusted HRs for lung cancer were 2.67 (95% CI, 2.09-3.4) for never-smokers with COPD and 1.97 (95% CI, 1.75-2.21) for ever-smokers without COPD. Risk was even higher for ever-smokers with COPD (adjusted HR = 6.19; 95% CI, 5.04-7.61), according to the data.
“Interestingly, the risk of lung cancer development in never-smokers with COPD was similar to the risk observed in ever-smokers without COPD,” the researchers wrote. “Given that poor lung function in COPD is often a barrier to optimal lung cancer treatment due to increased risk of treatment-related morbidities, our study suggests that early detection of lung cancer in COPD patients may reduce the risk of treatment complications.”
For their study, the researchers included 338,548 Korean citizens aged 40 to 84 years from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) who had at least one health check provided by the NHIS from 2002 to 2013. During 2,355,005 person-years of follow-up, 1,834 participants developed lung cancer, with incidence rates of 4.9 per 1,000 person-years among participants with COPD and 0.7 per 1,000 person-years among participants without or before development of COPD.
The researchers noted that the study had several limitations, including that the effect of COPD severity on lung cancer incidence could not be assessed because spirometry data were unavailable. Information on environmental and occupational exposures and severity of emphysema were also lacking. Misclassification of disease may have also been possible due to the use of claims data for evaluation of clinical outcomes and COPD and lung cancer diagnoses.
Overall, though, the results from the study suggest COPD is a strong independent predictor of lung cancer, according to the researchers.
“Patients with COPD are at a high risk of lung cancer and future studies should evaluate whether COPD patients are candidates for lung cancer screening, irrespective of smoking status,” they wrote. – by Melissa Foster
Disclosures: The authors report no relevant financial disclosures.