Successful treatment with erlotinib of severe neutropenia induced by gefitinib in a patient with advanced non-small cell lung cancer

Neutropenia is a rare side effect of gefitinib and was scarcely reported in many large-scale randomized phase III trials using gefitinib monotherapy as first-line treatment. Clinicians should be aware that gefitinib-induced neutropenia in patients with non-small cell lung cancer can be treated successful by switching to erlotinib.