Bladder cancer overview

Bladder cancer is the sixth most common cancer in the United States, with more than 80,000 new cases diagnosed each year. It’s more prevalent among men than women—men are four times more likely to develop bladder cancer—and mainly develops in adults older than age 55, according to the American Cancer Society (ACS). Most people are diagnosed around age 73.

This cancer affects the bladder, the organ that collects urine after it’s made in the kidneys. During urination, the bladder tightens, and the urine leaves the bladder through a tube (the urethra) and exits the body. The lining of the bladder (the urothelium) is made of urothelial cells. Ninety percent of bladder cancers develop in urothelial cells. This type of bladder cancer is called transitional cell carcinoma (TCC).

Bladder cancer forms when cells in the bladder start multiplying uncontrollably. These abnormal cells typically develop within the tissue layer lining the inside of the bladder. There are many layers of muscle and tissue that make up the bladder wall, which surrounds the bladder's inner chamber.

Over time, as these cancerous cells multiply, they grow deeper into the bladder wall. Once they reach the outermost layer of bladder tissue, they may spread to nearby organs or tissues and, eventually, to faraway organs or parts of the body (metastasis).

For roughly half of all bladder cancer patients, a diagnosis is made before the cancer extends beyond the bladder wall's inner layer, when it’s easier to treat. These are called noninvasive bladder cancers.

Invasive bladder cancers, which have invaded farther into the bladder wall, account for about a third of cases diagnosed. About 4 percent of bladder cancers have reached distant organs by the time they’re diagnosed, according to the ACS.

Genetic changes, or mutations, alter the process by which healthy cells grow, divide and die. When specific mutations occur in genes that control these processes, cells start dividing too fast or surviving longer than intended, and the cells become cancerous.

People may inherit mutations from their parents (inherited mutations) or acquire them over their lifetime (acquired mutations). Some inherited gene changes are known to raise the odds of getting bladder cancer, but most of the gene changes associated with bladder cancer are acquired, not inherited.

While the exact causes of bladder cancer are not always known, the most common risk factors are age and gender. Other risk factors include:

• Family history
• Inherited gene mutations or hereditary cancer syndrome
• Smoking
• Chronic bladder infections
• Long-term use of catheters

Early-stage bladder cancer may not produce symptoms. But as the disease progresses, many symptoms are related to urination. It's important for patients to make a doctor’s appointment if they experience:

• Blood in the urine
• Frequent and/or painful urination Inability to urinate
• Pain in the lower back
• Urge to urinate when the bladder isn’t full

These symptoms may be caused by a problem other than bladder cancer, such as a urinary tract infection, bladder stones or an enlarged prostate.

The most common type of bladder cancer is called urothelial carcinoma, or transitional cell carcinoma. Urothelial carcinoma begins in the inner lining of the bladder, in bladder cells called urothelial cells. Urothelial cells may be found in the bladder's inner lining and the kidneys, ureters and urethra. Almost all people with bladder cancer have this type. The other, much rarer types of bladder cancer include:

• Squamous cell carcinoma
• Adenocarcinoma
• Small cell carcinoma
• Sarcoma

If a patient is experiencing symptoms associated with bladder cancer, and other causes are ruled out, the doctor may recommend other tests. These diagnostic tests may include:

• Rectal or vaginal exam
• Cystoscopy
• Imaging tests, including X-ray, ultrasound, MRI (magnetic resonance imaging) and intravenous pyelogram (IVP)
• Biopsy
• Lab tests, including advanced genomic testing and urine tests
• Bone scan

Bladder cancers are split into stages ranging from stage I to stage IV based on how far the cancer has spread. Doctors determine the stage of bladder cancer through various procedures. Many of these tests may be done during the diagnosis process, but additional tests may be necessary.

The treatment for bladder cancer depends largely on its stage. Doctors need to know whether the cancer has spread and, if so, where.

The stage plays a significant role in predicting how well a cancer may respond to treatment. Besides the cancer stage, other factors that play a role in the severity of bladder cancer and how it’s treated include:

• Age
• Medical history
• Extent of the cancer’s spread into the bladder wall
• Grade of the cancer—how similar the cancer cells are to healthy bladder cells, which may affect how fast they grow and spread

The approach to treating bladder cancer depends on the patient’s age, health history and stage, among other factors. The decisions should be made in close collaboration between patient and doctor, taking into account any concerns about side effects and personal preferences. Commonly used treatment options for bladder cancer include:

• Surgery
• Radiation therapy
• Chemotherapy
• Immunotherapy
• Targeted therapy

In addition to these treatment options, new therapies are always being studied in clinical trials. Before proceeding with treatment, patients may want to ask their doctor whether enrolling in a clinical trial would be the right approach.