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

Introduction: 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. Methods: Report of a case. Results: 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. Conclusion: 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. Please cite this paper as: Um S‐J, Lee S‐K, Yang DK, Son C, Roh MS, Kim KN, Lee K‐N and Choi PJ. Fatal interstitial lung disease after erlotinib administration in a patient with radiation fibrosis. The Clinical Respiratory Journal 2009; 3: 181–184.