I. Concept Tumor screening refers to a series of targeted medical tests that are performed when the body is healthy or without any symptoms. These screening methods can help to ensure the detection of early or curable tumors that are already present in the body. The selection of tumor screening methods and approaches should firstly consider the epidemiological and other relevant factors of the patient, the specificity and accuracy of the screening methods, and the affordability of the patient. Due to the rapid development of medical technology, tumor screening methods have become more and more accurate, but also more and more complicated and expensive. Therefore, when choosing a screening method or approach, the patient needs to spend some time talking to an oncologist, who will give a targeted screening method or approach after a thorough evaluation of the patient. In addition, the doctor will inform the patient of the advantages, limitations or possible hazards of these screening methods so that the patient can make an informed and reasonable decision. Screening for several common cancers 1. Breast cancer All women should be aware of any subtle changes in their breast and communicate these changes to their medical professionals in a timely manner. For women between 20 and 39 years old, we recommend that you have a physical examination (palpation) every one to three years, and for women 40 years old and above, we recommend that you have a mammogram every year along with a physical examination. Please schedule your own exams. For women with high-risk factors, such as family history of cancer, previous history of breast cancer, etc., we recommend that you discuss with your doctor the advantages and disadvantages of early mammogram screening and the timing of starting it, as well as other related investigations (such as ultrasound or MRI) or increasing the frequency of screening. 2.The screening methods for early lung cancer have been constantly changing internationally and domestically. Since the 1990s, low-dose spiral CT has been used to screen early lung cancer, and after years of international clinical trial data, it has been proved that this method is the best means to detect early lung cancer. The key screening groups include people who are 45 years old or older, or have a long-term smoking history with a smoking index of 20 pack-years or more (number of years of smoking x number of packs smoked per day), or work in a confined environment for a long time, or work in a bad environment with a lot of dust particles for a long time, or have a family history. 3.For people with the following high-risk factors for liver cancer, we recommend annual ultrasound examination and, if necessary, liver enhancement CT examination. The risk factors include: long-term heavy drinkers, chronic hepatitis B patients, patients with cirrhosis of the liver, and people who work with chemicals for a long time. It is recommended that men start prostate cancer screening at the age of 50, and that men aged 50 and above have an annual finger check and prostate-specific antigen (PSA) test by a physician. For those with a family history of prostate cancer, we recommend starting these tests at age 45. 5.Cervical cancer can be completely avoided by strict early screening methods and close follow up. Screening for cervical cancer should be started 3 years after the first sexual intercourse – TCT and pelvic examination should be performed once a year, and after 30 years of age, depending on the risk factors, those with negative results after 3 or more consecutive examinations can choose to reduce the number of examinations. 6.Gastric cancer, portal cancer, esophageal cancer For the above three cancers, upper gastrointestinal tract imaging is preferred for screening. Upper gastrointestinal tract imaging should be performed every 2 years. For those with the following high-risk factors, we recommend gastroscopy (once a year): diagnosed long-standing gastric ulcer, patients with long-term chronic atrophic gastritis, patients with atypical hyperplasia found by gastroscopy, and patients with long-term follow-up. For all patients with positive upper gastrointestinal imaging results, we recommend follow-up gastroscopy. 7. Colorectal cancer screening is recommended from the age of 50 years, and subjects, male or female, should follow one of the following screening methods: colonoscopy —- every 10 years (preferably performed by a medical specialist at an oncology hospital); fecal occult blood test (FOBT) —- once a year or stool immunohistochemistry test; sigmoidoscopy — every 5 years; fecal occult blood test or immunohistochemical test (annually) and sigmoidoscopy (once every 5 years) —- Performing both tests together is better than performing only one of them. All positive test results (F0BT, FIT, sigmoidoscopy) should be followed up with a colonoscopy.