Partial response to sorafenib treatment associated with transient grade 3 thrombocytopenia in a patient with locally advanced thyroid cancer

ABSTRACT

Advanced radioactive refractory and progressive or symptomatic differentiated thyroid carcinoma (DTC) is a rare condition. Sorafenib was recently approved for the treatment of these patients. We present the case of a 67 year old woman diagnosed with DTC who underwent a total thyroidectomy with central, lateral-compartment neck dissection and shaving of the trachea and esophagus due to tumor infiltration. A local recurrence was detected 14 months later requiring, additionally, two tracheal rings resection. The patient received a cumulative 131I dose of 650 mCi and developed dysphagia and dyspnea 63 months after initial surgery. A 18FGD-PET/CT showed progression of the local mass associated to hypermetabolic pulmonary nodules. Sorafenib 800 mg/day was then prescribed. A dose reduction to 400 mg/day was necessary due to grade 3 thrombocytopenia that appeared four months after drug prescription. Platelet count went to normal after this dose reduction. Five months after initiation of sorafenib, a partial response of the local mass with significant intra-tumoral necrosis was observed. We conclude that sorafenib is a valid option for locally advanced DTC and that the platelet count should be evaluated regularly because it seems that thrombocytopenia might be more frequently observed in DTC than in other types of tumors.