Fatal interstitial lung disease after erlotinib administration in a patient with radiation fibrosis

Abstract

Although gefitinib used for the treatment of non-small-cell lung cancer is a well-known cause of interstitial lung disease (ILD), few case reports on erlotinib-induced ILD have been issued. The common risk factor of both of these two drug-induced ILDs is idiopathic interstitial pneumonia, but ILD in a patient with radiation fibrosis has not been previously reported. Report of a case. We recently experienced a case of fatal erlotinib-induced ILD, diagnosed based on clinical and radiologic findings, which occurred in a patient with radiation fibrosis. A 50-year-old male patient was started on erlotinib as a third-line chemotherapy. Six days after taking erlotinib, a chest radiograph showed rapid progression of reticular infiltration in both lung fields. High-resolution computed tomography scan findings were consistent with ILD, which was sufficient to diagnose as erlotinib-induced ILD. The patient died of respiratory failure after 8 days of steroid infusion and erlotinib discontinuation. Our case shows a fatal side effect of erlotinib. This case had radiation fibrosis, so we suggest that radiation fibrosis may be another contributor of the occurrence of ILD in patients taking erlotinib.