Prostate cancer is one of the most common malignancies of the male genitourinary system. In the United States, the incidence of prostate cancer ranks first among all malignant tumors in men, and the mortality rate ranks second only to lung cancer. At present, China has entered an aging society, and with the increase of life expectancy, change of diet structure, and improvement of tumor screening and diagnosis, the incidence rate of prostate cancer in China is much lower than that of western developed countries, but it has been on the rise in recent years, and is now the 3rd malignant tumor of male genitourinary system, which has gradually become one of the important tumors that seriously affect the life and health of men in China. Unlike other common malignant tumors of the urinary system, prostate cancer does not have typical clinical symptoms because it occurs mostly in the peripheral zone of the prostate gland, and early prostate cancer is mostly confined to the prostate gland without invading the surrounding tissues of the prostate gland, so there is often no obvious clinical manifestation. However, as the tumor progresses, it will show a variety of different clinical symptoms. Lower urinary tract symptoms: including irritation and obstruction symptoms. First of all, it should be clear that lower urinary tract symptoms are not unique to prostate cancer, but are more often seen in many benign lesions of the urinary system. In patients with prostate cancer, when the tumor infiltrates into the anterior middle of the prostate gland and invades the urethra, bladder neck and triangle, it can cause lower urinary tract symptoms. These include urinary frequency, urgency, hesitation, interruption of urination, dribbling after urination, and difficulty in urination. Local infiltrative symptoms: Prostate cancer tends to grow and develop along the weakest pathways. Most prostate cancers originate in the peripheral zone of the prostate, which is behind the prostate, so the cysto-rectal space is often the first area invaded by locally invasive prostate cancer. If the tumor invades the prostate envelope and its nearby perineural lymphatics, it may cause perineal pain and sciatica; if the tumor invades and compresses the vas deferens, it may cause low back pain and testicular pain; if the tumor invades the upper part of the cysto-rectal space, it may compress the ureter and cause unilateral or bilateral hydronephrosis, which may cause renal failure in severe cases; if the tumor invades the neurovascular bundle at the back of the prostate, it may also cause In severe cases, when the tumor invades the rectum, it may cause difficulty in defecation or colonic obstruction; incontinence may occur when the tumor invades the urethra. Metastatic symptoms: The most common site of metastasis of prostate cancer is the bones, but sometimes it may also metastasize to other organs, such as the lungs, liver, and adrenal glands. Bone metastasis of prostate cancer may cause bone pain and even pathological fracture; tumor metastasis to pelvic lymph nodes may cause lower limb edema; tumor metastasis to lung may cause coughing and coughing blood. Systemic symptoms: Advanced prostate cancer may manifest as wasting and weakness, low fever, progressive anemia, cachexia or kidney failure. It can be seen that the early symptoms of prostate cancer patients are atypical and cannot be detected through early clinical manifestations, while prostate cancer is often at an advanced stage when certain clinical symptoms appear. Since the key to improving the treatment effect of prostate cancer is early diagnosis and early treatment, prostate cancer screening is particularly important for the treatment effect of the disease. Screening for prostate cancer refers to the application of simple and effective screening methods to detect the tumor early before the patient develops the related symptoms. The common screening methods include DRE, PSA, TRUS, MRI and TRUS-guided transrectal prostate puncture biopsy, among which DRE and PSA are the most common and basic screening methods. In some developed countries in Europe and America, prostate cancer screening programs are more aggressive due to the high incidence of prostate cancer. For example, the American Urological Association (AUA) and the American Society of Clinical Oncology (ASCO) recommend that men over the age of 50 should receive routine DRE and PSA examinations every year, and for men with a family history of prostate cancer should start at the age of 45. The Guidelines for the Diagnosis and Treatment of Prostate Cancer developed in China recommend that men over the age of 50 with lower urinary tract symptoms should routinely undergo PSA and DRE, and men with a family history of prostate cancer should begin these tests at age 45. However, in recent years, as the understanding of prostate cancer has improved, some scholars have also raised the issue of overtreatment, arguing that such extensive screening does not improve the overall survival of patients with prostate cancer. The jury is still out on this issue. However, the general principle is that screening should be preceded by full communication with the patient about the pros and cons of screening and making the final decision. Rectal examination is one of the most economical and basic tests for prostate cancer screening. 15% to 40% of prostate cancer patients can have abnormalities detected during rectal examination, but the diagnostic accuracy is low and closely related to the clinical experience of the physician. In addition, most of the prostate cancers detected by rectal examination are intermediate and advanced prostate cancers, and the combination with PSA can significantly improve the diagnostic rate. PSA is a single chain glycoprotein with serine protease activity in the prostate tissue. When the prostate tissue is cancerous, a large amount of PSA enters the blood circulation after the normal tissue is destroyed making the PSA in the blood elevated. There are many factors that affect P S A levels, such as prostatitis, prostate enlargement and acute urinary retention, prostate biopsy, cystoscopy, rectal examination, ejaculation, transurethral surgery, etc. can increase serum PSA levels; while some drugs, such as finasteride, can decrease serum PSA levels. In other words, PSA is a prostate tissue-specific antigen, but it is not specific to prostate cancer, and the above-mentioned influencing factors should be considered when testing PSA. The PS A test should be performed 24 hours after ejaculation; 48 hours after rectal examination, cystoscopy, catheterization and other operations; 1 week after prostate massage; and 1 month after prostate puncture; the test should be free of acute prostatitis, urinary retention and other diseases, so that the P S A test results are more accurate and credible, and have more clinical significance and value. Other screening methods, such as transrectal ultrasound (TRUS) examination, prostate MRI examination, TRUS-guided transrectal prostate puncture biopsy, etc., are often further tests performed to clarify the diagnosis when abnormalities are found on rectal finger examination or PSA examination. As the life expectancy of our population has increased and the standard of living has improved, prostate cancer has become one of the most common malignant tumors of the male genitourinary system in China, and early detection and early treatment is the key to cure prostate cancer.