The prevalence of pulmonary fibrosis combined with emphysema in patients with lung cancer

Background and objective: Combined pulmonary fibrosis and emphysema (CPFE) is a unique disorder of the upper lobe, whereas emphysema is usually associated with lower lobe fibrosis. Although CPFE might increase the risk of lung cancer, the prevalence of CPFE in patients with lung cancer and the incidence of lung cancer in patients with CPFE are unknown. The objective of this study was to determine the prevalence of CPFE in lung cancer patients and to assess the clinical features of these patients. Methods: A total of 1143 patients with lung cancer were reviewed. Based on HRCT performed at diagnosis of lung cancer, patients were categorized into four groups: normal, emphysema, fibrosis and CPFE. The clinical characteristics of patients with CPFE were compared with those of the other groups. Results: CPFE, emphysema and fibrosis were identified in 101 (8.9%), 404 (35.3%) and 15 (1.3%) patients with lung cancer, respectively. The median overall survival of CPFE patients (n = 101, 10.8 months) was significantly less than that of normal patients (n = 623, 53.0 months) or that of patients with emphysema alone (n = 404, 21.9 months). Acute lung injury occurred in 20 (19.8%) patients with CPFE. Conclusions: CPFE is more prevalent than fibrosis in patients with lung cancer, and patients with CPFE had a poorer prognosis in the present study. Further investigation is therefore necessary to elucidate whether CPFE is an independent risk factor for lung cancer.