What is urothelial carcinoma?
Urothelial carcinoma is cancer that starts in your urothelium, the tissue that lines parts of your urinary system. Urothelial carcinoma accounts for about 90% of all cases of bladder cancer and 7% of all cases of kidney cancer, including cancer in your renal pelvis and ureter. Bladder and kidney cancers caused by urothelial carcinoma have similar symptoms. They also have similar prognoses — caught early on, these cancers are easily treated, but often come back.
How does urothelial carcinoma affect my body?
Urothelial carcinoma may affect your bladder and kidneys in different ways.
Urothelial carcinoma in your bladder
Your bladder is a triangle-shaped organ that’s centered between your hipbones, above your urethra and below your kidneys. Pee (urine) from your kidneys drains into your bladder, which is lined with tissue called urothelium. Urothelium is made of cells that stretch when your bladder fills with pee and collapses when it’s empty. (Your bladder can hold about 2 cups of pee.)
In bladder cancer, abnormal urothelial cells spread from the inner lining to other layers deep in your bladder. The abnormal cells may also spread through your bladder wall into the fatty tissues that surround your bladder. Left untreated, bladder cancer may grow through your bladder walls to nearby lymph nodes and then other areas of your body, including your bones, lungs or liver.
Bladder cancer can be high-grade or low-grade:
- High-grade urothelial carcinoma may be life-threatening. It often comes back after treatment. It may spread into the muscle layer of your bladder, to other areas in your body and to your lymph nodes.
- Low-grade urothelial carcinoma may come back (recur), but rarely spreads into your bladder’s muscle layer or other parts of your body.
Urothelial carcinoma in your kidneys
Most people have two kidneys. Kidneys are bean-shaped organs that sit just below your ribcage and behind your belly. Your kidneys clear toxins and waste from your blood by producing pee (urine) that collects in your renal pelvis located in the middle of each kidney. From there, your pee drains through a long tube drains that connects your kidney to your bladder. This tube is your ureter. Like your kidneys, your renal pelvis and ureter are lined with urothelial tissue.
In kidney cancer, abnormal urothelial cells form tumors in your kidneys, renal pelvis or ureter. Kidney cancer may spread to other organs or tissues.
Who is affected by urothelial carcinoma?
Bladder cancer is the sixth most common cancer in the U.S. Urothelial bladder cancer represents 90% of all cases of bladder cancers. Men and people assigned male at birth (AMAB) are four times more likely to develop bladder cancer than women and people assigned female at birth (AFAB).
Kidney cancer is the eighth most common cancer. Urothelial kidney cancer represents about 7% of all kidney cancers. Kidney cancer is most common in people between the ages of 65 and 74. Men and people AMAB are twice as likely as women and people AFAB to develop the disease.
