[A case of multidrug-resistant non-small cell lung cancer responding to TS-1].

A 72-year-old man was admitted to our hospital, complaining of exertional breathlessness. Chest radiograph revealed a right pleural effusion. Cytology for pleural effusion revealed adenocarcinoma; thus, he was diagnosed with advanced lung cancer (clinical stage T 4 N 0 M 0, Stage IIIB). Since tumor recurrence occurred despite CBDCA+gemcitabine, docetaxel, gefitinib and vinorelbine administrations, he received fifth-line oral chemotherapy using TS-1 at 120 mg/day (80 mg/m(2)/day) for 28 days, followed by withdrawal for 14 days. Chest computed tomography showed a partial response. Hematologic and non-hematologic toxicities were mild with the TS-1 administration. TS-1 could be an effective agent for treatment of multidrug-resistant non-small cell lung cancer.