1. The increase is mainly in the best treated papillary thyroid cancer Thyroid cancer is different from the usual thyroid nodules and is a malignant tumor that occurs in the thyroid gland, including papillary, follicular, medullary, and undifferentiated carcinomas. According to studies, papillary thyroid cancer has the highest survival rate after treatment, accounting for nearly 90% of the total thyroid cancer incidence. This type of thyroid cancer is also predominant in the recent increase in the number of thyroid cancers. In contrast, the incidence of follicular, medullary, and undifferentiated carcinomas has not changed significantly over the past decades. 2. The high incidence is due to medical advances The use of two tests, ultrasound and cytopathological techniques in thyroid cancer screening, is one of the most important factors in the high incidence of thyroid cancer.