Local treatments and TKI efficacy in radioiodine refractory differentiated thyroid carcinoma patients: a single center experience

A cohort of radioiodine-refractory differentiated thyroid cancer patients (RAI-R DTC) in a tertiary center underwent therapeutic interventions according to disease progression rate and metastasis location. We evaluated the independent impact of local and/or systemic treatments on final outcomes in 122 RAI-R DTC patients (44.3% men, age at diagnosis 51.98 ± 15.8 years) who were followed up for 9.5 years (1.4-50). Patients were divided into two groups: those with only locoregional persistent disease: group 1, n = 27 (22.1%) and those with distant metastases: group 2, n = 95 (77.9%). Patients from group 1 underwent mainly local procedures. The final outcome was 4/27 (14.8%) partial-response (PR) and 23/27 (85.2%) stable disease (SD). Of group 2 patients, 10/95 underwent active surveillance for micrometastatic disease, and the remaining received either only local treatments (40/95) or TKIs ± local treatments (45/95). The final outcome was PR in 7/95 (7.4%), SD in 38 (40%) and progressive disease in 50 (52.6%). Concerning group 2 in Kaplan-Meier analysis, local metastasis stabilization with local and/or systemic therapy had a favorable effect on survival (P < 0.02). Those treated with TKIs + local procedures, despite having more aggressive tumors, achieved more frequently local stabilization and had a similar outcome compared to those treated with only TKIs (P = 0.007). For group 2, in Cox proportional hazard analysis during the follow-up period, younger age at diagnosis and maintenance of tumor differentiation are predictors of more favorable OS and cancer-specific survival. In conclusion, the implementation of local procedures in RAI-R DTC management stabilizes metastatic lesions and potentially enhances survival. Further studies are warranted to validate these findings.