Characteristics of and Risk Factors for Interstitial Lung Disease Induced by Chemotherapy for Lung Cancer

Background: Drug-induced interstitial lung disease (DILD) is generally a serious adverse effect and almost always necessitates the discontinuation of the offending drug. Cancer pharmacotherapy is strongly associated with DILD, and the risk of DILD has been suggested to be higher in patients with lung cancer because of preexisting pneumonic disease. Objective: The aim of this retrospective study was to identify the risk factors and prognostic factors for early death from interstitial lung disease (ILD) induced by chemotherapy for lung cancer. Methods: The medical records of 459 patients who underwent chemotherapy for lung cancer between April 2007 and March 2013 were analyzed with regard to patient background and DILD development, initial symptoms, and prognosis. Results: A total of 33 patients (7.2%) developed chemotherapy-induced ILD. The most frequently observed initial symptom was dyspnea (94.3%). Preexisting ILD was identified as a risk factor for DILD (odds ratio [OR] = 5.38; 95% CI = 2.47-11.73; P < 0.01). Among the 33 patients who developed DILD, 10 patients suffered an early death despite steroid therapy. Poor prognostic factors included epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) use (OR = 9.26; 95% Cl = 1.05-82.0; P < 0.05) and 2 or more prior chemotherapy regimens (OR = 6.95; 95% CI = 1.14-42.3; P < 0.05). Conclusions: Many lung cancer patients have coexisting ILD, and these patients have a high risk of developing chemotherapy-induced ILD. In addition, patients with DILD who underwent EGFR-TKI therapy and 2 or more prior chemotherapy regimens had a higher risk of fatal outcome.