Clinical Characteristics of Synchronous Multiple Lung Cancer Associated With Idiopathic Pulmonary Fibrosis

To define the clinical characteristics of multiple lung cancer (LC) associated with idiopathic pulmonary fibrosis (IPF), we reviewed 154 LC patients associated with IPF: 23 patients with synchronous multiple LC (IPF-multiple LC group) and 131 with single LC (IPF-single LC group), and these were compared with 4,931 patients with LC from 1975 to 1977 in Japan (whole LC group). In the IPF-single and IPF-multiple LC groups, most tumors were observed in male patients (91% and 96%), smokers (94% and 100%), and in peripheral regions of the lung (91% and 98%). The incidence of occurrence in the lower lobes, where a fibrotic shadow was prominent, was significantly higher in the IPF-LC groups (58% and 67%) than for the whole LC group (37%). The distribution of histologic types in the IPF-single LC group was similar to that of the whole LC group. However, the incidence of small cell carcinoma was significantly higher in the IPF-multiple LC group (33%) than for the IPF-single LC (14%) and whole LC (12%) groups. These results indicate that the features characteristic to synchronous multiple LC in patients with IPF are as follows: (1) male patients; (2) smokers; (3) small cell carcinoma histologic type; (4) lower lobes; and (5) peripheral type, all of which show a high rate of occurrence. To define the clinical characteristics of multiple lung cancer (LC) associated with idiopathic pulmonary fibrosis (IPF), we reviewed 154 LC patients associated with IPF: 23 patients with synchronous multiple LC (IPF-multiple LC group) and 131 with single LC (IPF-single LC group), and these were compared with 4,931 patients with LC from 1975 to 1977 in Japan (whole LC group). In the IPF-single and IPF-multiple LC groups, most tumors were observed in male patients (91% and 96%), smokers (94% and 100%), and in peripheral regions of the lung (91% and 98%). The incidence of occurrence in the lower lobes, where a fibrotic shadow was prominent, was significantly higher in the IPF-LC groups (58% and 67%) than for the whole LC group (37%). The distribution of histologic types in the IPF-single LC group was similar to that of the whole LC group. However, the incidence of small cell carcinoma was significantly higher in the IPF-multiple LC group (33%) than for the IPF-single LC (14%) and whole LC (12%) groups. These results indicate that the features characteristic to synchronous multiple LC in patients with IPF are as follows: (1) male patients; (2) smokers; (3) small cell carcinoma histologic type; (4) lower lobes; and (5) peripheral type, all of which show a high rate of occurrence. Interstitial Pulmonary Fibrosis and Lung CancerCHESTVol. 108Issue 5PreviewDiffuse interstitial pulmonary fibrosis (DIPF), the prototypic restrictive lung disorder, has been long recognized as a chronic inflammatory process characterized by abnormal collagen deposition.1 In the majority of cases, the cause of DIPF remains idiopathic—Scadding's "cryptogenic fibrosing alveolitis.2 Full-Text PDF