From the moment it appears, cancer keeps transmitting its unique information to the outside world through various methods and channels. In other words, “cancer expresses itself through its unique voice and form”. These methods and channels of expression include: 1) special biochemical products 2) upstream and downstream signals transmitted by channels in cancer cells 3) mechanical compression of normal channels in the body by cancer masses 4) complications caused by tumor damage to tissues or organs Modern science and technology have devised various diagnostic methods in response to the various messages sent by cancer and their morphological appearance. These methods make “cancer knowable” a reality. Always remember: “Cancer speaks, it speaks a special language, listen to it and learn it.” In the early detection of cancer, it is especially important to mention routine and sequential examinations. Each type of cancer has specific early manifestations, and following the regular and sequential examinations from simple to complex can save both money and time. Here are some proven experiences. 1.Cough: more than a few weeks after conventional treatment, especially in middle-aged and elderly people, lung cancer is not excluded: chest X-ray. 2.Sputum blood: no explainable cause, blood in sputum does not exclude lung cancer. Chest X-ray. 3, hoarseness: ENT examination (including laryngoscopy), local biopsy, chest X-ray. 4.Esophagus: discomfort when eating. Barium esophagogram, esophagoscopy. 5.Gastric appetite: gradual loss of appetite and tasteless diet. g-I, gastroscopy, routine blood, stool occult blood test. 6, right upper abdominal discomfort: liver function, ultrasound. 7, abdominal pain, diarrhea, blood in stool: stool routine, occult blood, anal finger examination, barium enema angiography, fiberoptic enteroscopy. 8, hematuria: urine routine, urinary triple cup test, KUB X-ray imaging, cystoscopy, ultrasound examination of bladder and kidney. 9.Vaginal discharge: gynecological examination, colposcopy, hysteroscopy, diagnostic scraping, biopsy, ultrasound, tumor markers. 10.Anemia, bleeding, fever: blood routine, bone marrow examination for those with abnormal blood. 11.Bone and joint pain: plain film, ECT, CT. 12.Headache, abnormal sensory consciousness: routine neurological examination, cranial CT, cervical spine film, chest film. Cancer will definitely mess up and progress, so it will leave “traces”. Medical workers should learn to be a “Monkey King”-type “cancer scout”, and use a pair of “scouts” to detect cancer. Medical workers should learn to be a “Sun Wukong” type “cancer scout” and use a pair of “golden eyes” to tell the cancer to show its original shape. Cancer is an active and progressive disease, which will definitely release various metabolites into the environment (host body) during its development, and this is the origin of “tumor markers”. This is the origin of “tumor markers”. The human body is bound to react to the substances released by tumors, and the products of such specific reactions are also called tumor markers. Tumor markers have been measured since long ago to detect the presence of tumors. It was not until the 1960s, when the first marker related to liver cancer, alpha-fetoprotein (AFP), was introduced, that tumor markers really entered the history of cancer diagnosis and early diagnosis research and application.