Even for highly malignant tumors, the cure rate of most early stage is over 90%, such as early stage cervical cancer and early stage gastric cancer. The reason why we talk about cancer is that most of what we have found so far are middle and late stage cancers. We believe that we will overcome tumors sooner or later and make tumor cells change their ways. Early diagnosis is the main and effective means at present. Early diagnosis requires people to insist on regular checkups. For example, cervical cytology examination is required once a year for married women over 20 years old or women who have sexual intercourse, and once a year after 2 negative tests. It is often possible to monitor cancer 8-10 years before it occurs so that appropriate interruptions can be made to prevent the development of cancer. Fine needle aspiration of the thyroid can make a diagnosis at an early stage of cancer, allowing many patients to achieve early treatment, while making an accurate diagnosis of most benign lesions and avoiding unnecessary surgery and overtreatment. There are many other methods for early diagnosis, such as endoscopy of esophagus, stomach, colorectum, trachea and lung, biopsy of liver and breast on the basis of imaging, and pathology is needed to prove the final diagnosis of cancer.