Anlotinib in radioactive iodine-refractory differentiated thyroid cancer and the usefulness of SUVmax as an prognostic indicator.

Abstract

e18077 Background: Radioactive iodine-refractory differentiated thyroid cancer (RAIR-DTC) is characterized by poor therapeutic effect on radioactive iodine with poor prognosis. Therefore, a variety of molecularly targeted drugs are used in the treatment of RAIR-DTC. However, sorafenib and lenvatinib are not “broad-spectrum” anti-cancer drugs for RAIR-DTC. The efficacy and safety of Anlotinib in the treatment of RAIR-DTC need to be studied. Methods: From September 2020 to September 2021, 9 patients with RAIR-DTC were included. Follow-up continued until disease progression or intolerable adverse events occurred. Efficacy was evaluated by serum triglycerides (Tg) and imaging (RECIST1.1). Adverse events were also recorded. Gender, age, maximum standard unit value (SUVmax), tumor metabolic volume (MTV), total glycolysis (TLG), pathological type and tumor stage were included in the univariate analysis. Results: 8 patients reached the standard of “partial biochemical remission”. The average Tg level of these 8 patients decreased by 74.8% after Anlotinib treatment. 15 target lesions (TLs) were found in 6 patients. The average reduction ratio of TLs in these 6 patients was 28.7%. Furthermore, we observed three (50%) PR, three (50%) SD, with an ORR of 50% and a DCR of 100% in these 6 patients. The severity of AEs in all 9 patients did not exceed Grade 2. The most common AEs were hand-foot skin reactions, diarrhea, and hypertension, which accounted for 5/9, 3/9, and 3/9, respectively. Serious drug-related AEs did not occur. The average decrease in Tg after 3 courses was significantly greater in the high metabolism group (TL SUVmax 27.9) compared with the average decrease in the low metabolism group (TL SUVmax < 7.9), with 83.25% and 16.11% respectively (p = 0.027). There was no correlation between age, gender, pathological type, staging, other metabolic indexes of PET/CT and the ratio of patients' Tg reduction. Conclusions: Anlotinib can be used for the treatment of RAIR-DTC. This study confirmed the efficacy of Anlotinib with a high disease control rate. SUVmax can be used as an indicator to predict the therapeutic effect of Anlotinib in RAIR-DTC patients.