Interstitial pneumonia during gefitinib treatment of non-small-cell lung cancer.

Gefitinib, an orally active, selective inhibitor of epidermal growth factor-receptor tyrosine kinase, is an effective treatment for patients with advanced non-small-cell lung cancer (NSCLC). Most drug-related adverse events are mild to moderate; however, some patients may develop acute interstitial pneumonia that is sometimes fatal. In a prospective study of gefitinib in 76 patients with advanced NSCLC, 69 patients were evaluable for toxicity, and 4 cases (5.8%) of gefitinib-related interstitial pneumonia were diagnosed: 1 occurred in the second week; 2 in the second month; and 1 during the fourth month of treatment. When interstitial pneumonia occurred, the patients had stable disease (n = 2), a partial response (n = 1), or progressive disease (n = 1). All 4 patients recovered when gefitinib treatment was stopped and glucocorticosteroid therapy was started; no deaths related to gefitinib therapy were noted in this series. While treating NSCLC patients with gefitinib, it is important to carefully evaluate any new-onset respiratory symptoms and promptly arrange radiographic examinations, and to stop gefitinib treatment and begin glucocorticosteroid therapy whenever pulmonary toxicity is highly suspected.