Metastatic paraganglioma and treatment with sunitinib: a case report.

Sunitinib malate is a small kinase inhibitor with activity against a number of tyrosine kinase receptors. We treated a young man suffering from a metastatic paraganglioma with sunitinib. In this report we discuss a number of related questions including the correct dosage, schedules and timing of administration of the molecule, the main side effects and their treatment, and evaluation of the treatment response by CT scan. Treatment with sunitinib started at a dose of 50 mg daily for 4 weeks followed by 2 weeks off (4/2). Because of the side effects, the dose was reduced to 25 mg daily (4/2) and then to 25 mg daily (2/1). This resulted in a significant decrease in the plasma chromogranin A value and the radiological size of the metastases, as well as important clinical improvement. After 6 cycles the treatment was stopped because of a rise in plasma NSE values and disease progression. Sunitinib malate can induce marked toxicity, in which case the daily dose should be reduced and a different schedule of administration adopted. Response evaluation by CT scan should take into account tumor necrosis caused by sunitinib. Sunitinib malate is an interesting molecule for targeted therapy also for advanced neuroendocrine tumors. There has been evidence of significant clinical improvement, as in the case reported here.