Abstract
A patient with adenocarcinoma of the lung was treated sequentially using two kinds of EGFR tyrosine kinase inhibitors, gefitinib and erlotinib. The patient was a 73-year-old female who received gefitinib as a second line treatment, which resulted in a partial response with response duration of 6 months. After progression of the disease, the patient received erlotinib, which resulted in partial response again with response duration of 11.5 months. This observation suggests that treatment with erlotinib may be effective in patients who develop progressive disease after a primary treatment with gefitinib following an initial response.