Risk of malignancy in patients with asthma-COPD overlap compared to patients with COPD without asthma

I:Chronic low-grade inflammation as in asthma may lead to a higher risk of malignancy. The aim of this study was to determine if asthma is associated with an increased risk of cancer, among COPD patients. M:Nationwide cohort study based on COPD outpatients with or without concomitant asthma. Patients with Asthma-COPD(ACO) were propensity score-matched (PSM)1:2 to COPD-patients without asthma (COPD-W/O-A). We calculated the risk of any cancer diagnosis within two years of follow-up. Separately, incidence of lung cancer was also analysed in the patients with ACO and the COPD-W/O-A. ICS was explored as a possible risk modifier. R:50,897 COPD outpatients were included of whom 88% without prior malignancy. Twenty percent had ACO. In the PSM-cohort, 26,003 COPD-patients without prior malignancy were analyzed, as well as 3,331 patients with prior malignancy. There was no association between ACO and cancer events (HR=0.9,CI=0.8-1.1, p=0.31) in patients without prior malignancy and neither(HR=1.04,CI=0.85-1.26, p=0.74) in patients with prior malignancy as compared to COPD-W/O-A. The signal was unchanged in regard to lung cancer. ICS did not seem to alter the risk of cancer(HR 0.99(0.73-1.36)). C: ACO nor ICS therapy were associated with cancer events. Our study supports the current practice, i.e. that concomitant asthma diagnosis does not prompt a different approach when assessing the need for diagnostic cancer work-up.