Study of Anlotinib Hydrochloride Capsules in the Treatment of Locally Advanced or Metastatic Radioiodine-Refractory Differentiated Thyroid Carcinoma

This study is testing anlotinib (a targeted therapy that blocks tumor blood vessel growth) for people with thyroid cancer that has spread or is locally advanced and no longer responds to radioactive iodine treatment, which is the standard approach for thyroid cancer. **You may be eligible if...** - You are between 18 and 70 years old - You have differentiated thyroid cancer (a common type) that has spread or cannot be removed with surgery - Your cancer has grown in the past 18 months without iodine treatment, or your tumor no longer absorbs iodine - You are in good overall health (ECOG score 0–1) with at least 6 months expected survival **You may NOT be eligible if...** - You still respond well to radioactive iodine treatment - You are older than 70 - You are in poor health that would prevent treatment Talk to your doctor to see if this trial is right for you.