According to the American Cancer Society, approximately 70,000 Americans are diagnosed with bladder cancer each year. Bladder cancer is nearly three times more common in men than in women and is most common in people over age 70.
The bladder is an expandable, hollow organ in the pelvis where urine is stored until it is emptied from the body through the urethra. The wall of the bladder has several layers including the surface cells, which expand and deflate (the transitional epithelial cells), smooth muscle, and a fibrous layer. The extent to which the cancer has penetrated these layers influences a patient’s treatment and prognosis.
Types of Bladder Cancer
Many bladder cancers can be cured, but getting the best outcome requires close cooperation from a team of specialists.
Transitional cell carcinoma (TCC), also known as urothelial carcinoma, is the most common form of bladder cancer and accounts for nearly 90 percent of cases. About 70 percent of TCC cases are noninvasive, meaning that the cancer is confined to the lining of the bladder and is unlikely to spread. The other 30 percent of TCC cases are more advanced. In these patients, either the cancer has penetrated the bladder’s lining and grown into the muscular wall of the bladder (called muscle-invasive bladder cancer), or it has spread, or metastasized, to other organs.
Less common bladder cancer types include squamous cell carcinoma, which accounts for about 8 percent of cases, and small cell carcinoma and adenocarcinoma, both of which account for only 1 to 2 percent of bladder cancer cases in the US.
While most cases of bladder cancer in industrialized nations such as the US, Canada, and France are transitional cell carcinomas, in developing countries, 75 percent of cases are squamous cell carcinomas caused by infection with the parasitic organism Schistosoma haematobium.
Risk factors for different types of cancer are traits and behaviors that increase the likelihood that an individual will develop disease. Risk factors for bladder cancer include behaviors such as cigarette smoking as well as inherited (genetic) traits and exposure to cancer-causing agents in the environment.
- Smoking Cigarette smoking is the most significant risk factor for bladder cancer. In fact, smokers are twice as likely to develop bladder cancer as nonsmokers. Smoking is estimated to be responsible for 47 percent of bladder cancer deaths among men and 37 percent among women. At Memorial Sloan-Kettering, patients with bladder cancer who are smokers are referred to our smoking cessation program, which offers individual and group counseling to help people overcome their habit. Research has shown that quitting smoking will reduce the likelihood of developing a recurrence of bladder cancer.
- Genetics A number of substances, some of them carcinogenic, or cancer-causing, can become concentrated in the urine and increase a person’s chances of getting bladder cancer. Memorial Sloan-Kettering investigators are working to discover how the body removes cancer-causing agents such as smoke and chemicals. Studies suggest that certain genetic traits cause some individuals to detoxify these carcinogens more slowly than others, possibly increasing their risk of developing the disease.
- Occupation Certain occupations have been linked to an increased risk for bladder cancer. People who work in the textile, dye, rubber, leather, printing, or paint industries are at higher risk for the disease because of their exposure to a class of organic chemicals called aromatic amines.
- Chronic Bladder Problems Studies have linked bladder cancer with long-term bladder problems, such as bladder infections and bladder and kidney stones. Chronic irritation of the bladder can also predispose people to bladder cancer.
- Cyclophosphamide Therapy People who have taken the drug cyclophosphamide (Cytoxan®), which is often used as a treatment for lymphoma, are at higher than average risk for bladder cancer.
The most common symptom of bladder cancer is blood in the urine, which is not always visible to the naked eye and is usually not accompanied by pain. People may delay seeing their doctor because this bleeding is intermittent or irregular, thereby delaying the diagnosis of bladder cancer. Other symptoms include an increased frequency of urination, an increased urgency to urinate, feeling the need to urinate but not being able to do so, and painful urination.
If you have one or more of these symptoms, it does not mean that you have bladder cancer. However, it is important to see a doctor so that if you do have an illness it can be diagnosed and treated as early as possible.