Current trend in incidence of severe interstitial lung disease (ILD) due to gefitinib in Japan

Abstract

e19075 Background: Although gefitinib is a promising agent for the treatment of advanced non-small cell lung cancer, ILD occurs in Japanese patients and sever ILD sometimes becomes fatal toxicity. ILD has been reported to be associated with preexisting ILD, smoking, and poor performance status. On the other hand, it has been reported that female gender, adenocarcinoma, non-smoker, and EGFR mutation are associated with sensitivity to gefitinib. Methods: To investigate the trend in incidence of severe ILD and patient characteristics receiving gefitinib, a total of 751 patients who were administered gefitinib in National Cancer Center Hospital East between 2002 and 2008 were retrospectively reviewed. To investigate how oncologists avoid administering gefitinib to patients with preexisting ILD, pretreatment chest CT films of all patients were also reviewed by two thoracic radiologists. Results: The patient number who received gefitinib in 2002/2003/2004/2005/2006/2007/2008 were 134/141/88/93/125/98/72, respectively. In these patients, percentages of female were 36/43/42/55/59/52/54%, adenocarcinoma 76/78/93/88/95/93/92%, non-smoker 35/30/40/53/49/48/46%, respectively. Almost all of the patient receiving gefitinib was recently restricted to adenocarcinoma. Grade 3–5 severe ILD was observed in 1.9% of all patients. However, the incidence rate of sever ILD were decreased as 3.0/2.8/2.3/1.1/0.8/1.0/1.4%, respectively. The rates of patients with preexisting ILD were also decreased as 22/14/15/5/2/3/6%, respectively. Conclusions: The correct information about efficacy and severe ILD about gefitinib influenced patient selection by oncologists, and it is reasonable to select more effective and safe patients in Japan. It is estimated that the incidence rate of severe ILD should be consequently controlled by the spread of these information. No significant financial relationships to disclose.