Discontinuation of the tyrosine kinase inhibitor sunitinib in patients with metastatic renal cell carcinoma: a case series.

PURPOSE: Tyrosine kinase inhibitors (TKI) play a pivotal role in the modern treatment of patients with metastatic renal cell carcinoma (mRCC). Depending on the course and the response, the targeted therapy may last for years. Thus the question arises, if a successful treatment leading to a complete response or at least a stable disease after a partial remission, may be discontinued. MATERIALS AND METHODS: Here we present 3 patients with mRCC treated with sunitinib for at least one year, resulting in a partial response, followed by a stable disease for several years. In these patients, the treatment was interrupted for different medical reasons. RESULTS: After a period of 20, 33 and 34 months, respectively, the metastases of the renal cell cancer showed no signs of progression, neither clinically nor in computed tomography scans, but the side effects of TKI or the medical problem leading to treatment interruption resolved in all patients within a few weeks. CONCLUSION: The discontinuation of the treatment for mRCC with TKI seems to be possible, even in those patients with a partial response only, but no complete remission has been achieved before.

Long lasting efficacy of sorafenib in a heavily pretreated patient with thymic carcinoma.

Thymoma and thymic carcinoma are rare neoplasms of the mediastinum, arising from the epithelial cells of the thymus. While surgical resection is the treatment of choice in early stages, platin-based chemotherapy is mainly used in patients with advanced or metastatic disease; however, the prognosis is poor. Here we present the case of a 54 year old female patient suffering from a CD117-negative thymic carcinoma with widespread metastases. After several courses of different kinds of chemotherapy, finally these approaches failed to be effective. Thus we initiated a treatment with sorafenib, an inhibitor of several receptor tyrosine kinases. The treatment was tolerated very well, and within a few weeks the general condition of the patient improved significantly. A CT-scan, performed 3 months after therapy with sorafenib started, showed a 50 % reduction of tumor size, and this effect lasted for 15 months. When the carcinoma relapsed again, we administered another course of chemotherapy and, because of lacking success, we even tried to use sunitinib. However, the patient died in a septic shock, based on progressive disease. In summary, we present a patient with metastastic thymic carcinoma, in which sorafenib led to a tumor-control for 18 months.