Gefitinib-induced interstitial lung disease showing improvement after cessation: disassociation of serum markers.

Gefitinib (ZD1839), a small-molecule epidermal growth factor receptor tyrosine kinase inhibitor, is an anticancer agent for patients with non-small cell lung carcinoma. Recently, however, as a result of accumulating evidence, it has been recognized that gefitinib can give rise to lethal lung toxicity. The authors report a case of interstitial lung disease (ILD) induced by gefitinib, which improved promptly following cessation of the administration of the agent. Clinical signs suggesting a good prognosis were noted, namely, findings similar to acute eosinophilic pneumonia on CT and a disassociation in the elevation of specific serum markers of ILD. At the time of onset of ILD, serum concentrations of surfactant protein (SP)-A and SP-D were significantly increased, whereas that of KL-6 was not increased. A previous study of three cases of lethal lung toxicity resulting from gefitinib administration revealed a significant and almost equal increase in KL-6, SP-A and SP-D. These results suggest that SP-A and SP-D may be indicators of gefitinib-induced ILD and that KL-6 is a predictor of outcome. Using a combination of these markers may help to establish a differential prognosis in patients with gefitinib-induced ILD.