[Chemotherapy for thymic carcinoma]

Thymic epithelial neoplasm is a quite rare malignancy arising from the thymic epithelium, and comprises thymoma, thymic carcinoma, and thymic neuroendocrine carcinoma. The incidence of thymic carcinoma and neuroendocrine carcinoma is much less than thymoma, accounting for 1-4%of anterior mediastinal tumors. These rare tumors are called"orphan tumors,"and standards of clinical management(including chemotherapeutic regimens)have not yet been determined for them yet because of their rarity. In the advanced setting, palliative-intent chemotherapy has been applied using cisplatin-based triplet or quartet chemotherapy with second-generation antitumor drugs, with reference to chemotherapeutic regimens for invasive thymoma such as ADOC, CAP, and VIP chemotherapy. However, biological plausibility is lacking for this approach, given that these tumors differ from thymoma in their expression of cellular surface proteins such as c-Kit and epidermal growth factor receptors. While limited to thymic carcinoma, platinum doublet chemotherapy with a third-generation antitumor drug as first-line chemotherapy is anticipated to offer the same clinical efficacy as multiple-agent combination chemotherapy, but with less toxicities. In second-line or later-lines of chemotherapy, single-agent chemotherapy may be optimal. Molecular biological approaches have been under investigation, but molecular targeted agents remain unavailable.