Early-stage prostate cancer generally has no symptoms, but if the patient also has prostate enlargement, or in cases of mid to late-stage prostate cancer where the tumor invades the urethra or bladder, various degrees of urinary obstruction or irritative urinary symptoms may occur. This is characterized by frequent urination and urgency. If there are local infiltrative symptoms, perineal pain and sciatica might occur. If the vas deferens is compressed, it can cause back pain and pain in the testicles on the affected side. Invasion of the rectum can cause difficulty in defecation or obstruction of the colon, and if the membranous part of the urethra is involved, urinary incontinence may occur. The most common site of metastasis for prostate cancer is the bones. If it spreads to the bones, it can cause bone pain, pathological fractures, anemia, and spinal cord compression leading to paralysis of the lower limbs.