Prostate cancer is a common disease among elderly men, with a very high incidence in Europe and the United States. Currently, the incidence of prostate cancer in the United States has surpassed that of lung cancer, becoming the first tumor that endangers men’s health. With the increasing life expectancy in China, the change of diet structure and the improvement of diagnostic technology, the incidence rate has increased rapidly in recent years. Healthy older men and prostate cancer patients know some knowledge about prostate cancer diagnosis, which can help prostate cancer disease prevention, early detection, and accurate and timely treatment. Who needs to be screened for prostate cancer? For men over 50 years old, annual PSA screening is recommended, but for those over 80 years old without prostate related symptoms, routine screening is not recommended; patients with prostate nodules detected by rectal and anal examinations or ultrasound should be screened; men with a family history of prostate cancer should also be actively screened. How is prostate cancer graded? The pathological grading of prostate cancer is based on the degree of glandular differentiation and the form of tumor growth to assess its malignancy, with the Gleason grading system being the most commonly used. Gleason 2-4 is a well-differentiated cancer; 5-7 is a moderately differentiated cancer; 8-10 is a poorly differentiated or undifferentiated cancer. Therefore, the common expression is G=? +? for example, Gleason 4+3=7. How is prostate cancer staged? The TNM staging system is mostly used for prostate cancer, which is divided into 4 stages, T: stage is divided into Tla stage: the volume of incidental tumor is <5% of the volume of the resected tissue, and the rectal examination is normal; Tlb stage: the volume of incidental tumor is >5% of the volume of the resected tissue, and the rectal examination is normal; Tl. T2 stage is divided into T2a stage: tumor is confined to and <1/2 of a single lobe; T2b stage: tumor is confined to and >1/2 of a single lobe; T2c stage: tumor invades both lobes but is still confined to the prostate; T3 stage is divided into T3a stage: tumor invades and breaks through the envelope of one or both lobes of the prostate; T3b stage: tumor invades the seminal vesicles. T4 stage: the tumor invades the bladder neck, external urethral sphincter, rectum, levator muscle and/or pelvic wall. In order to understand the pelvic lymph nodes and distant metastases, further pelvic enhancement CT and whole body bone scan are usually performed after a good puncture to diagnose prostate cancer How is prostate cancer diagnosed clinically? Diagnostic rectal examination, transrectal ultrasound and serum prostate-specific antigen (PSA) are the basic methods for clinical diagnosis of prostate cancer. Rectal examination can reveal prostate nodules with a firm texture. Transrectal ultrasound can reveal hypoechoic lesions in the prostate, their size and extent of invasion. The diagnosis of prostate cancer can be made by MRI, which is superior to other imaging methods, and can be considered if there are low signal nodules or diffuse hypoechoic areas in the peripheral zone of the prostate with high signal on T: weighted images. For stage C and D tumors, both CT and MRI can show invasion of extraperitoneal, seminal vesicles, bladder neck, and enlarged lymph nodes in the pelvis. IVU may reveal advanced prostate cancer infiltrating the bladder and compressing the ureter causing hydronephrosis. Whole-body nuclide bone imaging and MRI can detect bone metastases at an early stage. How is prostate cancer diagnosed? The diagnosis of prostate cancer is made by systematic puncture biopsy of the prostate gland under the guidance of transrectal or perineal ultrasound, based on the presence or absence of cancer. Although it is more susceptible to infection than the perineal route, the choice of puncture route is increasing due to its high positive biopsy rate. The choice of puncture route should be carefully considered according to the experience of the doctor, the location of the prostate tumor and the actual condition of the patient. The number of needles used for puncture is also the same, the more needles used the more accurate the diagnosis, but also the more damage. Which patients should have a prostate puncture biopsy? in order to decide the treatment plan; ④ patients with existing metastatic cancer and clinical suspicion that the primary cancer is in the prostate. What are the misconceptions of prostate cancer diagnosis? Prostate cancer is a disease of the elderly, which generally develops slowly and has a long course. It is generally not recommended to diagnose prostate cancer in patients over 80 years of age with a predicted life expectancy of less than 10 years, especially for puncture diagnosis. On the other hand, premature diagnosis has obvious adverse psychological effects on patients, and even premature endocrine therapeutic interventions reduce the survival time and quality of life of patients. Of course, for patients younger than 75 years old who are in good general condition and can undergo radical surgery, the earlier the diagnosis is made, the better the treatment effect may be.