Clinical significance of combined pulmonary fibrosis and emphysema

Abstract

Combined pulmonary fibrosis and emphysema (CPFE) is not a distinctive disease, but the coexisting pattern with heterogeneous conditions. Identifying patients with CPFE is important because of its unique clinical features including natural history. We reviewed the medical records of 154 patients with an UIP pattern, identified on HRCT or confirmed by surgical biopsy. Patients were divided into IPF and CPFE groups. Patients with CPFE (n=44, 28.6%) had upper lobe predominant emphysema more than 10% of affected lungs. Paraseptal emphysema was the most common. The CPFE group had significantly higher number of male (p=0.001) and smokers (p=0.04) than the IPF group. There were significant differences in FVC, FEV1/FVC, TLC and DLco between groups. In the GAP stage, stage II was more common in the CPFE group, and stage I in the IPF group (p=0.001). Lung cancer was more common in the CPFE group (27.3 vs. 8.2 %, p=0.002). There was no significant difference in cell type, stage, or location including relationship to the fibrotic area. Overall survival was worse in the CPFE group. Mortality associated with lung cancer was more common in the CPFE group (21.4 vs. 9.1 %). Mortality associated with IPF was more common in the IPF group (84.8 vs. 50.0 %) (both, p=0.035). Except the number of smokers and the amount they smoked, patients with IPF including CPFE cases had no significant difference between without and with lung cancer (13.6%). Identification of patients with CPFE has significant clinical implications, including increased risk of complicated lung cancer and lung cancer-related mortality. We recommend distinguishing CPFE from IPF because CPFE showed relatively high incidence in IPF and worse clinical outcomes than IPF.