Activity and safety of sunitinib in patients with advanced radioactive iodine-refractory differentiated thyroid carcinoma in clinical practice

Our aim was to evaluate the effectiveness of off-label use of sunitinib in patients with advanced differentiated thyroid carcinoma (DTC) refractory to radioactive iodine (RAI) therapy. We performed a retrospective analysis of patients treated in the setting of clinical practice in a University General Hospital. Eleven consecutive patients (5 women, 6 men, mean age 63.0 ± 12.9 year) with advanced papillary (n = 7) or follicular (n = 4) thyroid carcinoma not suitable for curative surgery or RAI therapy were studied. Two patients were treated with one line of tyrosine kinase inhibitors before sunitinib therapy. All patients had evidence of objective progressive disease (PD). We analysed the objective response rate (ORR) and changes in thyroglobulin levels during therapy. Complete response was achieved in 1 patient (9 %) and partial response (PR) in 2 patients (18 %). Five patients (45 %) had stable disease (SD). Therefore, ORR was 27 % and disease control rate was 72 %. We found that the decrement in thyroglobulin concentrations was significantly higher in patients with radiological disease control than in patients with PD. Most frequent grade 1 and 2 adverse events were fatigue, mucositis, hand-and-foot syndrome, hyporexia, rash, hypertension, and edema. In routine clinical practice, sunitinib appears to be effective and feasible in patients with advanced RAI-refractory DTC. Most patients achieved SD or PR, despite having PD at the start of treatment, and safety profile was consistent with that reported in previous clinical trials.