There are four main types of thyroid cancer, including papillary thyroid cancer, follicular carcinoma, medullary carcinoma, and undifferentiated carcinoma, with papillary thyroid cancer being the most common in clinical practice, with a high rate of metastasis to the lymph nodes in the neck, followed by follicular carcinoma. Treatment relies primarily on surgery, and all types except undifferentiated carcinoma are insensitive to radiotherapy and chemotherapy.
The surgical approach is still controversial. For micro papillary carcinoma, one lobe plus isthmus is mostly used, for multiple carcinomas, bilateral total thyroidectomy is required, and for follicular carcinoma, bilateral total thyroidectomy is required. The first step in the process is to take thyroxine and achieve endocrine suppression to maintain thyroid function and prevent recurrence after surgery for papillary and follicular thyroid cancer.
Iodine-131 therapy is not indicated for tumors that do not invade the thyroid envelope and do not have lymph node metastases; if lymph node involvement or lesions that break through the thyroid envelope are found, or if distant metastases are found, iodine therapy is usually recommended to effectively remove residual lesions and metastases, especially in papillary and follicular thyroid cancers.