Children tested with RET gene mutation have high risk of developing cancer in the future. Can the detection of RET gene mutation prevent the occurrence of hereditary medullary thyroid cancer? Theoretically speaking: RET gene mutation is a somatic mutation, all cells in human body contain RET gene, once mutated, all RET genes in all cells will be mutated, there is no way to stop it. In other cancers, there are only mutated genes in cancer cells. If there is a RET gene mutation, there is a possibility of disease. The current medical level is not yet able to stop the gene mutation, and treatment can only be given when the disease is not developed or just developed. What kind of treatment is usually given? Surgery or medication? Medullary thyroid cancer can only be treated by surgery, preferably at an early stage. Are pediatric patients at risk treated after the onset of the disease or is prophylactic removal performed before the onset of the disease? In the United States, hereditary medullary thyroid cancer is treated before the disease develops; in China, there are no clear treatment protocols, and doctors figure out the timing of treatment based on experience. If prophylactic thyroidectomy is performed and pathology results show that there is no cancerous tissue in the thyroid after resection, there may be legal issues. Therefore, in order to better adapt to the national situation, we usually perform resection when the disease has just developed. Medullary thyroid cancer is divided into four stages, with stage I being the earliest and stage IV being the most advanced. According to treatment experience, stage I patients are basically 100% curable, while the cure rate for stage IV patients is only 20%-40%. So taking treatment when the patient first develops the disease (stage I), the effect will be very good. After detecting the RET gene mutation, you need to review it regularly, and once cancer is detected, it can be treated immediately, right? Theoretically, it is.