What is bladder cancer?
The urinary bladder is a hollow, flexible organ made mostly of muscle. The bladder is part of the body’s urinary system, along with the kidneys, ureters, and urethra.1,2 In the urinary system, the two kidneys filter out waste and extra water from the bloodstream to produce urine. The ureters are two thin tubes, connected to each kidney, that carry urine out of the kidneys and into the bladder, where it is stored until a person urinates. During urination, the muscles of the bladder tighten and allow urine to flow out of the body through the urethra, which is another thin tube. A person develops bladder cancer when some of the cells inside of the bladder become cancerous, which changes the way they grow and divide. Unlike healthy cells, which grow and die off in a regular and controlled way, cancer cells grow in an uncontrolled way and do not die off like healthy cells. Cancer cells can then begin to crowd out the healthy cells. Bladder tumors develop when cancer cells in the bladder mass together.
How does it grow?
There are different types of bladder cancers, but around 90% of people diagnosed with bladder cancer in the United States have a type called urothelial carcinoma.1,2 The urothelium is a thin layer of cells that lines the inside of the bladder. Most bladder cancers begin to grow in the lining of the bladder. If the bladder cancer cells are located only in the bladder lining, a patient is diagnosed with non-muscle-invasive bladder cancer. If the cancer cells have grown deeper into the muscle of the bladder wall, a patient is diagnosed with muscle-invasive bladder cancer. Bladder cancer that has spread outside the bladder, but only in areas close to the bladder, is referred to as locally advanced bladder cancer. If the bladder cancer cells have started to grow in areas of the body distant from the bladder, then the patient is diagnosed with metastatic bladder cancer.
Are there common risk factors?
Researchers have identified several risk factors for bladder cancer. Having one or more risk factors makes a person more likely to develop bladder cancer, but does not mean that the person will definitely develop it.3 Some risk factors for bladder cancer cannot be controlled, such as age, gender, and ethnicity. In the United States, risk factors for bladder cancer include being older, being male, and being Caucasian/White American.
However, there are other risk factors for bladder cancer that can be controlled. For example, smoking and tobacco use are estimated to cause around half of bladder cancers and non-smokers are approximately three times less likely to develop bladder cancer than people who smoke. Workplace exposure to certain harmful substances is also a risk factor. Regularly drinking water from a source that contains arsenic or chlorine can increase a person’s risk of bladder cancer, and people who do not drink enough water each day also may have a higher risk of developing it.
What are the symptoms and how is it diagnosed?
Blood in the urine is by far the most common symptom of bladder cancer, which is experienced by between 80% and 90% of patients diagnosed.4,5 It is often the first symptom the patient notices, and it is sometimes the only symptom.
Bladder cancer can cause other symptoms related to urination, which are also called irritative bladder symptoms. Around 20% to 30% of patients diagnosed with bladder cancer experience one or more irritative bladder symptoms. These include:
- Needing to urinate more frequently than usual
- Feeling pain or burning before, during, or after urinating
- Feeling the urgent need to urinate despite having a bladder that is not full
- Difficulty urinating despite a full bladder
If a patient has blood in the urine or other urinary symptoms, healthcare providers often use a multi-step diagnostic process to determine if the symptoms are due to bladder cancer or to some other cause. The process of diagnosis may include:
- Medical history and physical examination
- Examination under anesthesia
- Urine tests
- Transurethral resection of bladder tumor (TURBT)
- Imaging tests
How is it treated?
If a patient is diagnosed with bladder cancer, there are many different treatment options available.6 The type of treatment or treatments a patient receives depends upon the patient’s type of cancer, overall health, and other factors. Most patients diagnosed with bladder cancer are treated with surgery of some kind, such as:
- Transurethral resection of a bladder tumor (TURBT)
- Radical or partial cystectomy
- Reconstructive surgery
- Lymph node dissection
- Laser ablation therapy
In addition to surgery, patients may receive a type of chemotherapy delivered directly into the bladder, called intravesical chemotherapy. Another potential type of treatment that is also delivered directly into the bladder is called Bacillus Calmette-Guerin (BCG) immunotherapy treatment. Radiation therapy and systemic chemotherapy may also be used, sometimes in combination, to treat patients with bladder cancer, with or without surgery. For certain patients with advanced or metastatic bladder cancer, immunotherapy medications are a relatively new potential treatment option.