Bladder cancer forms in tissues of the bladder (the organ that stores urine). Most bladder cancers are transitional cell carcinomas (cancer that begins in cells that normally make up the inner lining of the bladder). Other types include squamous cell carcinoma (cancer that begins in thin, flat cells) and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids). The cells that form squamous cell carcinoma and adenocarcinoma develop in the inner lining of the bladder as a result of chronic irritation and inflammation.
Transitional cell carcinoma: Cancer that begins in cells in the innermost tissue layer of the bladder. These cells are able to stretch when the bladder is full and shrink when it is emptied. Most bladder cancers begin in transitional cells.
Squamous cell carcinoma: Cancer that begins in squamous cells, which are thin, flat cells that may form in the bladder after a long- term infection or irritation.
Adenocarcinoma: Cancer that begins in glandular (secretory) cells that may form in the bladder after a long-term inflammation or irritation.
Cancer that is only in cells in the lining of the bladder is called superficial bladder cancer. The doctor might call it carcinoma in situ. This type of bladder cancer often comes back after treatment. If this happens, the disease most often recurs as another superficial cancer in the bladder.
Cancer that begins as a superficial tumor may grow through the lining and into the muscular wall of the bladder. This is known as invasive cancer. Invasive cancer may extend through the bladder wall. It may grow into a nearby organ such as the uterus or vagina (in women) or the prostate gland (in men). It also may invade the wall of the abdomen.
When bladder cancer spreads outside the bladder, cancer cells are often found in nearby lymph nodes. If the cancer has reached these nodes, cancer cells may have spread to other lymph nodes or other organs, such as the lungs, liver, or bones.When cancer spreads (metastasizes) from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if bladder cancer spreads to the lungs, the cancer cells in the lungs are actually bladder cancer cells. The disease is metastatic bladder cancer, not lung cancer. It is treated as bladder cancer, not as lung cancer. Doctors sometimes call the new tumor "distant" disease.
No one knows the exact causes of bladder cancer. However, it is clear that this disease is not contagious. No one can "catch" cancer from another person. People who get bladder cancer are more likely than other people to have certain risk factors. A risk factor is something that increases a person's chance of developing the disease. Still, most people with known risk factors do not get bladder cancer, and many who do get this disease have none of these factors. Doctors can seldom explain why one person gets this cancer and another does not. Studies have found the following risk factors for bladder cancer:
Age: The chance of getting bladder cancer goes up as people get older. People under 40 rarely get this disease.
Tobacco: The use of tobacco is a major risk factor. Cigarette smokers are two to three times more likely than nonsmokers to get bladder cancer. Pipe and cigar smokers are also at increased risk.
Occupation: Some workers have a higher risk of getting bladder cancer because of carcinogens in the workplace. Workers in the rubber, chemical, and leather industries are at risk. So are hairdressers, machinists, metal workers, printers, painters, textile workers, and truck drivers.
Infections: Being infected with certain parasites increases the risk of bladder cancer. These parasites are common in tropical areas but not in the United States.
Treatment with cyclophosphamide or arsenic: These drugs are used to treat cancer and some other conditions. They raise the risk of bladder cancer.
Race: Whites get bladder cancer twice as often as African Americans and Hispanics. The lowest rates are among Asians.
Being a man: Men are two to three times more likely than women to get bladder cancer.
Family history: People with family members who have bladder cancer are more likely to get the disease. Researchers are studying changes in certain genes that may increase the risk of bladder cancer.
Personal history of bladder cancer: People who have had bladder cancer have an increased chance of getting the disease again.
Chlorine is added to water to make it safe to drink. It kills deadly bacteria. However, chlorine by-products sometimes can form in chlorinated water. Researchers have been studying chlorine by-products for more than 25 years. So far, there is no proof that chlorinated water causes bladder cancer in people. Studies continue to look at this question.
Some studies have found that saccharin, an artificial sweetener, causes bladder cancer in animals. However, research does not show that saccharin causes cancer in people.
People who think they may be at risk for bladder cancer should discuss this concern with their doctor. The doctor may suggest ways to reduce the risk and can plan an appropriate schedule for checkups.
Treatment Options for Bladder Cancer
People with bladder cancer have many treatment options. They may have surgery, radiation therapy, chemotherapy, or biological therapy. Some patients get a combination of therapies.The doctor is the best person to describe treatment choices and discuss the expected results of treatment.
A patient may want to talk to the doctor about taking part in a clinical trial, a research study of new treatment methods. Clinical trials are an important option for people with all stages of bladder cancer.
Surgery is a common treatment for bladder cancer. The type of surgery depends largely on the stage and grade of the tumor. The doctor can explain each type of surgery and discuss which is most suitable for the patient:
Transurethral resection: The doctor may treat early (superficial) bladder cancer with transurethral resection (TUR). During TUR, the doctor inserts a cystoscope into the bladder through the urethra. The doctor then uses a tool with a small wire loop on the end to remove the cancer and to burn away any remaining cancer cells with an electric current. (This is called fulguration.) The patient may need to be in the hospital and may need anesthesia. After TUR, patients may also have chemotherapy or biological therapy.
Radical cystectomy: For invasive bladder cancer, the most common type of surgery is radical cystectomy. The doctor also chooses this type of surgery when superficial cancer involves a large part of the bladder. Radical cystectomy is the removal of the entire bladder, the nearby lymph nodes, part of the urethra, and the nearby organs that may contain cancer cells. In men, the nearby organs that are removed are the prostate, seminal vesicles, and part of the vas deferens. In women, the uterus, ovaries, fallopian tubes, and part of the vagina are removed.
Segmental cystectomy: In some cases, the doctor may remove only part of the bladder in a procedure called segmental cystectomy. The doctor chooses this type of surgery when a patient has a low-grade cancer that has invaded the bladder wall in just one area.
Sometimes, when the cancer has spread outside the bladder and cannot be completely removed, the surgeon removes the bladder but does not try to get rid of all the cancer. Or, the surgeon does not remove the bladder but makes another way for urine to leave the body. The goal of the surgery may be to relieve urinary blockage or other symptoms caused by the cancer.
When the entire bladder is removed, the surgeon makes another way to collect urine. The patient may wear a bag outside the body, or the surgeon may create a pouch inside the body with part of the intestine.