Systemic tumor screening is an important way to detect cancer and precancerous lesions at early stage, including laboratory tests, imaging tests and endoscopy. 1. Laboratory examination: blood sampling for tumor markers is suggestive of some tumors, including alpha-fetoprotein, neuron-specific enolase, carcinoembryonic antigen and so on. 2. Imaging examination: it mainly includes CT examination and MRI, and PET-CT can be used if necessary, which can detect the tumor more accurately and sensitively. 3. Endoscopy: including gastroscopy, enteroscopy, etc., which can visually find the tumor in the corresponding area, and endoscopic biopsy can also be done for pathology. It is recommended to ask the doctor’s opinion, choose the tumor screening program suitable for you, and have regular medical checkups for early detection of the disease.