The urethra is a tube that carries urine from the bladder to the outside of the body. In women, the urethra is about 1½ inches long and is just above the vagina. In men, the urethra is about 8 inches long. It goes through the prostate gland and the penis to the outside of the body. In men, the urethra also carries semen.

Urethral cancer is a rare cancer that occurs more often in men than in women. There are three types of urethral cancer. Squamous cell carcinoma is the most common type. It forms in the flat cells that line the urethra. Transitional cell carcinoma forms in cells near the urethral opening in women and in the part of the urethra that goes through the prostate gland in men. These cells change shape and stretch as urine passes out of the body. Adenocarcinoma forms in the glands near the urethra. These glands make and release mucus and other fluids.

Urethral cancer can metastasize (spread) quickly to tissues around the urethra and has often spread to nearby lymph nodes by the time it is diagnosed. Signs of urethral cancer include bleeding or trouble urinating.