Salvage chemotherapy with carboplatin and paclitaxel for cisplatin-resistant thymic carcinoma--three cases.

The optimal chemotherapeutic regimen for thymic carcinoma remains uncertain and the utility of salvage therapy has also not been reported. Three cases of unresectable and locally advanced thymic carcinoma, resistant to prior chemotherapy with cisplatin are reported. These patients were treated with carboplatin and paclitaxel chemotherapy, as salvage chemotherapy. Although concomitant thoracic radiotherapy was performed in one patient, two showed a partial response and the other showed a minor response after carboplatin and paclitaxel chemotherapy. Thymic carcinoma is sensitive to platinum-based chemotherapy and paclitaxel appears to have significant activity against thymic carcinoma. Thymic carcinoma differs from thymomas not only morphologically, but also biologically (1,2). Thymic carcinoma is a thymic epithelial neoplasm with cytological malignant features and a clinical course that tends to be much more aggressive than that of thymoma (2-6). Thymic carcinoma also tends to metastasize widely, which leads to a highly lethal course (2-6). Thus, the role of systemic chemotherapy may be important in the treatment of thymic carcinoma. Cisplatin-based chemotherapy has repeatedly been shown to benefit certain patients (4-8), but an optimal regimen and the role of second-line and/or salvage chemotherapy remain unclear. In this paper, three cases of unresectable and locally advanced thymic carcinoma treated with carboplatin (CBDCA) and paclitaxel, that were resistant to prior cisplatin-based chemotherapy, are described. Patients and Treatment Profiles From 2003 to 2006, three patients were diagnosed with unresectable thymic carcinoma. In each case, percutaneous computed tomography (CT) guide biopsy was performed and the lesions were confirmed histologically to be epidermoid- type thymic carcinoma. Clinical staging included medical history and physical examination, complete biochemical profile, chest radiographs, chest CT scans and bronchoscopy. In addition, to examine extrathoracic distant metastasis, abdominal and brain CT and bone scans were performed. According to the classification of Masaoka et al. (9), the patients had unresectable, locally advanced disease (IVa). All patients were initially treated with a combination of cisplatin (50 mg/m 2 ) and doxorubicin (40 mg/m 2 ) on day 1, vincristine (0.6 mg/m 2 ) on day 3, and cyclophosphamide (700 mg/m 2 ) on day 4 (ADOC chemotherapy). All drugs were administered intravenously. Partial response (PR) was defined as a decrease of more than 50% in the size of the main measurable lesions. Stable disease (SD) was defined as regression of less than 50% of measurable lesions. If measurable lesions increased or new lesions appeared after chemotherapy, the case was defined as showing progressive disease. Evaluation was performed after at least two courses of each chemotherapy regimen. The chemotherapy profiles of the three patients are summarized in Table I and the clinical courses, in each case, were as follows.