When prostate cancer invades surrounding tissues and structures, it can cause a variety of clinical symptoms, including urinary irritation, urinary obstruction, urinary incontinence, sciatica, erectile dysfunction, etc., and can compress causing unilateral or bilateral hydronephrosis. In severe cases, when the tumor invades the rectum, it can cause difficulty in defecation or colon obstruction. When the cancer metastasizes to the bones, it can cause bone pain and pathological fractures, and may also spread to the lungs.