Bladder cancer is one of the most common cancers, affecting approximately 68,000 adults in the United States each year. Bladder cancer occurs in men more frequently than it does in women and usually affects older adults, though it can happen at any age.
Bladder cancer most often begins in the cells (urothelial cells) that line the inside of your bladder — the hollow, muscular organ in your lower abdomen that stores urine. Although it's most common in the bladder, this same type of cancer can occur in other parts of the urinary tract drainage system.
About seven out of every 10 bladder cancers diagnosed start out at an early stage — when bladder cancer is highly treatable. However, even early-stage bladder cancer may recur in the bladder. For this reason, people with bladder cancer typically need follow-up tests for years after treatment to look for bladder cancer that recurs or advances to a higher stage.
Bladder cancer signs and symptoms may include:
- Blood in urine (hematuria)
- Painful urination
- Pelvic pain
If you have hematuria, your urine may appear bright red or cola colored. Sometimes, urine may not look any different, but blood in urine may be detected during a microscopic exam of the urine.
People with bladder cancer might also experience:
- Back pain
- Frequent urination
But, these symptoms often occur because of something other than bladder cancer.
Bladder cancer develops when cells in the bladder begin to grow abnormally. Rather than grow and divide in an orderly way, these cells develop mutations that cause them to grow out of control and not die. These abnormal cells form a tumor.
Causes of bladder cancer include:
- Smoking and other tobacco use
- Exposure to chemicals, especially working in a job that requires exposure to chemicals
- Past radiation exposure
- Chronic irritation of the lining of the bladder
- Parasitic infections, especially in people who are from or have traveled to certain areas outside the United States
It's not always clear what causes bladder cancer, and some people with bladder cancer have no obvious risk factors.
Types of bladder cancer
Different types of cells in your bladder can become cancerous. The type of bladder cell where cancer begins determines the type of bladder cancer. The type of bladder cancer determines which treatments may work best for you.
Types of bladder cancer include:
- Urothelial carcinoma. Urothelial carcinoma, previously called transitional cell carcinoma, occurs in the cells that line the inside of the bladder. Urothelial cells expand when your bladder is full and contract when your bladder is empty. These same cells line the inside of the ureters and the urethra, and tumors can form in those places as well. Urothelial carcinoma is the most common type of bladder cancer in the United States.
- Squamous cell carcinoma. Squamous cell carcinoma is associated with chronic irritation of the bladder, for instance from an infection or from long-term use of a urinary catheter. Squamous cell bladder cancer is rare in the United States. It's more common in parts of the world where a certain parasitic infection (schistosomiasis) is a common cause of bladder infections.
- Adenocarcinoma. Adenocarcinoma begins in cells that make up mucus-secreting glands in the bladder. Adenocarcinoma of the bladder is rare in the United States.
Factors that may increase bladder cancer risk include:
- Smoking. Smoking cigarettes, cigars or pipes may increase the risk of bladder cancer by causing harmful chemicals to accumulate in the urine. When you smoke, your body processes the chemicals in the smoke and excretes some of them in your urine. These harmful chemicals may damage the lining of your bladder, which can increase your risk of cancer.
- Increasing age. Bladder cancer risk increases as you age. Bladder cancer can occur at any age, but it's rarely found in people younger than 40.
- Being white. White people have a greater risk of bladder cancer than do people of other races.
- Being a man. Men are more likely to develop bladder cancer than women are.
- Exposure to certain chemicals. Your kidneys play a key role in filtering harmful chemicals from your bloodstream and moving them into your bladder. Because of this, it's thought that being around certain chemicals may increase the risk of bladder cancer. Chemicals linked to bladder cancer risk include arsenic and chemicals used in the manufacture of dyes, rubber, leather, textiles and paint products.
- Previous cancer treatment. Treatment with the anti-cancer drug cyclophosphamide increases the risk of bladder cancer. People who received radiation treatments aimed at the pelvis for a previous cancer have an elevated risk of developing bladder cancer.
- Chronic bladder inflammation. Chronic or repeated urinary infections or inflammations (cystitis), such as might happen with long-term use of a urinary catheter, may increase the risk of a squamous cell bladder cancer. In some areas of the world, squamous cell carcinoma is linked to chronic bladder inflammation caused by the parasitic infection known as schistosomiasis.
- Personal or family history of cancer. If you've had bladder cancer, you're more likely to get it again. If one of your first-degree relatives — a parent, sibling or child — has a history of bladder cancer, you may have an increased risk of the disease, although it's rare for bladder cancer to run in families. A family history of hereditary nonpolyposis colorectal cancer, also called Lynch syndrome, can increase the risk of cancer in the urinary system, as well as in the colon, uterus, ovaries and other organs.