Clinical Utility of Temozolomide in the Treatment of Malignant Paraganglioma: A Preliminary Report

We report on the efficacy and safety of short-term administration of temozolomide, an inhibitor of nucleoside incorporation, in a 60-year-old woman with widespread hepatic metastases from a malignant paraganglioma. Temozolomide was orally administered in daily doses of 250 mg on days 1 to 5 and repeated every 28 days for five cycles. Clinical improvement was immediate and associated with weight gain, and further reduction in blood pressure without orthostatic intolerance. In addition, abnormal hepatic function was normalized and catecholamine production was significantly reduced. Except for mild nausea, adverse effects were virtually absent. Bone marrow function, renal function, and serum electrolytes remained normal; hemoglobin remained above 9g/dl through treatment. The platelet count decreased but not to clinically meaningful levels. These responses allowed for a surgical debulking procedure to be performed safely without complications. The results suggest that temozolomide may be useful in presurgical preparation of patients with pheochromocytoma especially in those with widespread metastatic disease and poor physical condition. However, the present findings need confirmation in a larger study and the role of temozolomide in the long-term treatment of malignant paraganglioma/pheochromocytoma remains to be established.