First of all, all cancers need to be vigilant after diagnosis, specifically which three cancers do not need to be nervous about this statement is not scientific. Cancer is a malignant disease caused by a combination of internal and external factors such as heredity and environment. Usually, the main treatment after diagnosis is surgical resection, which can be supplemented by radiotherapy, chemotherapy, targeted therapy and other methods according to the condition. Since cancer is a life-threatening disease, it is necessary to be vigilant after diagnosis and cooperate with doctors in a timely manner. However, for some cancers with high clinical cure rate, such as papillary thyroid cancer, intraductal carcinoma in breast cancer, etc., and cancers with early stage, there is no need to be overly alarmed after diagnosis, and better prognosis can be achieved by actively cooperating with the treatment.