How many years does it take to get through the danger period after thyroid cancer surgery? It depends on the type of thyroid cancer, the effectiveness of the surgical treatment, and whether there has been a post-operative recurrence. The most common types of thyroid cancer with better prognosis are papillary cancer and follicular cancer. Even if accompanied by metastasis of neck lymph nodes, the prognosis of surgical resection is still good, and with lifelong taking of thyroxine after surgery, active prevention and treatment of complications, and prevention of metastasis and recurrence of cancer, the 5-year survival rate is usually very high, and the lethality rate is low. On the other hand, the prognosis and survival of undifferentiated thyroid cancer and medullary carcinoma are not as good as papillary adenocarcinoma and follicular carcinoma. They are highly malignant and prone to lymph node invasion and hematogenous metastasis, with very poor prognosis and low 5-year survival rate of less than 5%. Therefore, one should have regular thyroid checkups and early detection, diagnosis and treatment of thyroid cancer in order to maximize the survival rate.