In developed countries in Europe and America, most prostate cancer patients are detected and diagnosed at an early stage, and patients at this stage often do not have any discomfort; whereas most patients in China do not go to the doctor until they have difficulty in urination, bone pain and other discomforts, and most of them have already metastasized and lost the chance of cure. Therefore, it is especially urgent for prostate cancer patients in China to get early diagnosis. Screening for prostate cancer is the most effective means to diagnose prostate cancer at an early stage. It is recommended that men over 50 years old should undergo regular screening, and for men with a family history of prostate cancer, the screening should be advanced to 45 years old. For men with a family history of prostate cancer, screening should be done earlier than 45 years of age. The screening method includes a blood test for prostate-specific antigen (PSA) and an anal exam by a specialist. Prostate-specific antigen (PSA) is a substance produced by normal prostate or prostate cancer cells and can be measured by a blood test. Prostate-specific antigen (PSA) can be measured in normal men but is usually less than 4 sodium grams per deciliter (ng/dl). Most patients with prostate cancer will have elevated PSA values, but patients with prostatitis or prostate enlargement may also have elevated PSA values. The PSA cannot determine whether or not you have prostate cancer, but can only indicate the risk of prostate cancer. The higher the PSA value, the higher the risk of prostate cancer, and the urologist will need to perform a prostate puncture biopsy to confirm the diagnosis. An anal finger test is another important method of prostate cancer screening. The doctor wears gloves, applies lubricant and enters the anus with the index finger to understand the surface of the prostate by touch. The above-mentioned blood test for prostate specific antigen (PSA) and anal finger test cannot confirm the diagnosis of prostate cancer, but for those who suspect prostate cancer, a prostate puncture biopsy is needed to confirm the diagnosis. The doctor then uses an ultrasound-guided needle to puncture the prostate gland and obtain a small amount of prostate tissue for microscopic examination, and the doctor determines whether the prostate gland is cancerous or not based on the cellular pattern of the prostate tissue observed under the microscope. Most of the cancers diagnosed by prostate puncture biopsy are adenocarcinoma of the prostate, but very few are cancers from other organs of the body that have grown in the prostate. For prostate cancer, the pathologist will generally score the malignancy of the cancer, medically known as the Gleason score, which ranges from 2-10, the higher the score the more malignant the tumor is, and almost all clinically diagnosed prostate cancers are in the 5-10 range, with 5-6 being low malignancy, 7 being moderate malignancy, and 8-10 being highly malignant. Some men have no abnormalities on blood tests for prostate-specific antigen (PSA) and anal finger exams, and find prostate cancer unexpectedly after a type of surgery to remove part of the prostate. In some men, the prostate gland is significantly enlarged and presses on the urethra, which affects the urine discharge from the bladder and makes urination difficult. In this case, surgery is often required to remove a portion of the prostate gland to relieve the pressure on the urethra and achieve smooth urination. Doctors routinely perform pathological examinations (making sections to be examined by a pathologist under a microscope) on this part of the prostate gland, and sometimes the pathology is unexpectedly diagnosed as prostate cancer. Fortunately, these patients are often in the early stages and have a very good prognosis. Some patients go to the hospital because they have difficulty urinating, back pain or bone pain and other discomforts. The doctor performs an anal exam and draws blood to check the prostate-specific antigen (PSA) and then does a prostate puncture biopsy to confirm the diagnosis of prostate cancer, which is quite often found to be in the middle to late stage and poorly treated. In addition to the above tests, doctors often do magnetic resonance imaging (MRI), X-ray computed tomography (CT) and whole-body bone scan to find out whether the tumor has local and distant metastases.