A case of complete response treated by S-1 with concurrent radiotherapy for a gefitinib-resistant non-small cell lung cancer patient

A 35-year-old woman with a clinical diagnosis of stage T2N2M0 lung adenocarcinoma received 3 courses of preoperative chemotherapy with cisplatin and docetaxel. The treatment response was no change. A left inferior lobectomy with mediastinal and hilar lymph-node dissection (ND2a) was performed. The pathological diagnosis was stage T2N2M0 lung cancer. Gefitinib was administered postoperatively. After 2 months of oral treatment, gefitinib was discontinued because of enlarged subcarinal lymph nodes and an elevated level of serum Sialyl LewisX-i antigen (SLX). Starting 4 months after surgery, the mediastinum was irradiated with a total dose of 50 Gy. Chemotherapy with S-1 was started 5 months after surgery. S-1 was administered in a dose of 100 mg/day in two divided doses for 4 weeks, followed by 2 weeks of rest. The patient received 6 courses of chemotherapy with S-1, without increasing the dose. The enlarged mediastinal lymph nodes disappeared, and the serum SLX level returned to normal. The patient had a complete response, and was subsequently followed on an outpatient basis while receiving oral UFT. More than 36 months have elapsed since surgery, with no evidence of recurrence.