Efficacy Of Multikinase Inhibitors (Mkis) In Successive Treatment Lines Of Refractory Advanced Thyroid Cancer Patients (Pts)

e17553Background: Sequential therapy with MKIs in the management of refractory thyroid cancer cannot be standardized with data coming form randomized clinical trials. Methods: We retrospectively analyzed pts with advanced radioactive-iodine refractory differentiated thyroid cancer (DTC) or unresectable medullary thyroid cancer (MTC) treated with MKIs, from January 2010 to November 2015 included in the Spanish group of rare cancers (GETHI) database. Most used MKIs included sorafenib, lenvatinib, vandetanib, cabozantinib, sunitinib and pazopanib. Primary endpoint was to evaluate the progression-free survival in first-line (PFS1) compared to PFS in second-line (PFS2) independently of the MKIs used in both setting. Secondary objectives were overall survival (OS), overall response rate (RR) and overall safety profile. Results: 74 pts were analyzed (43 DTC, 31 MTC). All pts received MKIs in first-line (1st) and 43 (58.1%) in second-line (2nd). Median PFS1 was 11.53 months (CI 95% 11.53-14.5) and median PFS2 was...