It is not reliable to take blood test for tumor index to determine whether one has cancer or not. Most of the tumor indicators commonly used in clinical practice are non-specific, that is, tumors can cause abnormal tumor indicators, and benign diseases may also cause abnormal tumor indicators. The significance of tumor index test is to assist in the diagnosis of malignant tumor, that is, it must be combined with other examination results to make a comprehensive judgment, and another role is to serve as an indicator of the efficacy of anti-tumor treatment. In fact, regular blood sampling for tumor indexes and observation of dynamic changes of the indexes have greater clinical significance than the indexes themselves. Therefore, during the health checkup, blood sampling for tumor indicators should be combined with other examination results such as ultrasound, chest X-ray and CT as a means of tumor screening, and it is not reliable to rely on tumor indicators alone to determine the presence or absence of tumor.