After pathology confirms prostate cancer, doctors need to further evaluate the stage of prostate cancer, which means that they need to assess the local growth of prostate cancer within the prostate gland and the presence of metastases beyond the prostate gland, which is commonly referred to by the common people as whether the tumor is early, intermediate, or advanced. In order to predict the risk of tumor progression and metastasis in prostate cancer patients, the following information can usually be combined: the pre-puncture PSA value (stimulation of the prostate by puncture biopsy can cause an artificial increase in PSA over a month or even longer, so the pre-puncture PSA value needs to be used), the anal finger examination before puncture biopsy, the size of the Gleason score for prostate cancer on pathological examination, and the amount of tissue found by puncture The amount of prostate cancer tissue found on biopsy. In addition to the size of the PSA number, some physicians consider whether the PSA number is rising over time and how quickly it is rising. The following indicate that a patient with prostate cancer is at high risk for progressive metastasis: high PSA value (greater than 20ng/ml), high Gleason score (8-10), tumor growth beyond the prostate on anal finger examination, and large amount of tumor tissue on puncture pathology. According to the above criteria for assessing the risk of progressive metastasis of prostate cancer, whole-body bone scan and CT examination for staging are not recommended for patients with low risk, while for patients with moderate to high risk, whole-body bone scan, abdominal and pelvic CT examinations are recommended to find out whether prostate cancer has metastasized. Unfortunately, even if the test results are all normal, there is no guarantee that the tumor has not metastasized, because some metastatic lesions are too small to be detected by existing tests, and these tiny lesions will grow over time and will be detected on subsequent examinations. According to the local growth of prostate cancer in the prostate and the presence or absence of tumor metastasis beyond the prostate, prostate cancer can be divided into four stages. Stage I Low-grade malignant prostate cancer that is unexpectedly detected by postoperative pathological examination after prostatectomy for reasons other than prostate tumor and the tumor accounts for less than 5% of the examined tissue. Stage II Tumor is confined to the prostate gland but does not meet the criteria of stage I Stage III Tumor goes beyond the prostate gland and invades adjacent tissues or seminal vesicle gland but does not metastasize to other organs Stage IV Prostate cancer invades adjacent organs such as bladder, rectum, pelvic wall muscles; or prostate cancer metastasizes to pelvic lymph nodes; or prostate cancer metastasizes to other distant parts of the body. Prostate cancer stage is closely related to the treatment effect. Stage I, II and III prostate cancer all have the chance to be cured, but the cure rate is different for different stages, the lower the stage, the higher the cure rate, stage I cure rate is greater than stage II, stage II cure rate is greater than stage III. Stage IV patients whose tumors metastasize to bone or other distant sites have almost no chance to be cured, but only stage IV patients with pelvic lymph node metastasis can be cured in a small number of patients through active treatment.