Interstitial lung disease in Japanese patients with non-small cell lung cancer receiving gefitinib: An analysis of risk factors and treatment outcomes in Okayama lung cancer study group

Risk factors for the development of interstitial lung disease in patients with non-small cell lung cancer receiving gefitinib and the prognostic factors after interstitial lung disease development have not been established. The aim of this study was to retrospectively identify and evaluate these possible factors. PATIENTS AND METHODS We reviewed the clinical records and radiographs of 365 consecutive patients with non-small cell lung cancer who received gefitinib in West Japan between 2000 and 2003. RESULTS In total, 330 patients were eligible for interstitial lung disease evaluation, and 15 patients (4.5%) were finally confirmed to have developed interstitial lung disease by blinded expert review. Multivariate analysis revealed that preexisting pulmonary fibrosis, poor performance status, and prior thoracic irradiation were independent risk factors for interstitial lung disease, with odds ratios of 21.0 (95% confidence interval, 5.12-86.3, P < 0.0001), 9.70 (2.27-41.4, P = 0.001), and 4.33 (1.27-14.8, P = 0.019), respectively. Among the 15 patients who developed interstitial lung disease, eight have died of the condition. Short interval from the initiation of gefitinib treatment to the onset of interstitial lung disease, acute interstitial pneumonia pattern, and the presence of pre-existing pulmonary fibrosis were associated with poor prognosis. DISCUSSION Our results suggest the importance of patient selection for gefitinib treatment based on interstitial lung disease risk factors in the Japanese population identified.