Bladder Cancer

Overview

Bladder cancer refers to any of several types of malignant growths of the urinary bladder. It is a disease in which abnormal cells multiply without control in the bladder. Bladder cancer is the fourth most common cancer in Canadian men; with an estimated 3,700 new cases diagnosed each year. Men are two to three times more likely than women to get bladder cancer.

The wall of the bladder is lined with cells called transitional cells and squamous cells. More than 90 percent of bladder cancers begin in the transitional cells.

Cancer that is only in cells in the lining of the bladder is called superficial bladder cancer. This type of bladder cancer often comes back after treatment.

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 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 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.

Symptoms

Common symptoms of bladder cancer include:

  • blood in the urine
  • pain during urination
  • frequent need to urinate, often without results

These symptoms are not sure signs of bladder cancer. Infections, benign tumors, bladder stones, or other problems also can cause these symptoms. Anyone with these symptoms should see a doctor so that the doctor can diagnose and treat any problem as early as possible.

Causes

No one knows the exact cause or causes of bladder cancer. People who get bladder cancer are more likely than other people to have certain risk factors. 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 Canada.
  • Treatment with cyclophosphamide or arsenic. These drugs are used to treat cancer and some other conditions. They raise the risk of bladder cancer.
  • Race. Caucasians get bladder cancer twice as often as those of African descent. The lowest rates are among those of Asian descent.
  • 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.

Diagnosis

If a patient has symptoms that suggest bladder cancer, the doctor may check general signs of health and may order lab tests. The person may have one or more of the following procedures:

  • Physical exam -- The doctor feels the abdomen and pelvis for tumors. The physical exam may include a rectal or vaginal exam.
  • Urine tests -- The laboratory checks the urine for blood, cancer cells, and other signs of disease.
  • Intravenous pyelogram -- The doctor injects dye into a blood vessel. The dye collects in the urine, making the bladder show up on x-rays.
  • Cystoscopy -- The doctor uses a thin, lighted tube to look directly into the bladder to examine its lining. The patient may need anesthesia for this procedure.

The doctor can remove samples of tissue with the cystoscope. A pathologist then examines the tissue under a microscope. The removal of tissue to look for cancer cells is called a biopsy. In many cases, a biopsy is the only sure way to tell whether cancer is present. For a small number of patients, the doctor removes the entire cancerous area during the biopsy. For these patients, bladder cancer is diagnosed and treated in a single procedure.

If bladder cancer is diagnosed, the doctor needs to know the stage, or extent, of the disease to plan the best treatment. Staging is a careful attempt to find out whether the cancer has invaded the bladder wall, whether the disease has spread, and if so, to what parts of the body.

  • Stage 0 -- The cancer cells are found only on the surface of the inner lining of the bladder. The doctor may call this superficial cancer or carcinoma in situ.
  • Stage 1 -- The cancer cells are found deep in the inner lining of the bladder. They have not spread to the muscle of the bladder.
  • Stage 2 -- The cancer cells have spread to the muscle of the bladder.
  • Stage 3 -- The cancer cells have spread through the muscular wall of the bladder to the layer of tissue surrounding the bladder. The cancer cells may have spread to the prostate (in men) or to the uterus or vagina (in women).
  • Stage 4 -- The cancer extends to the wall of the abdomen or to the wall of the pelvis. The cancer cells may have spread to lymph nodes and other parts of the body far away from the bladder, such as the lungs

The doctor may determine the stage of bladder cancer at the time of diagnosis, or may need to give the patient more tests such as a CT scan, MRI, sonogram etc.

Treatment

The treatment of bladder cancer depends on how deep the tumor intrudes into the bladder wall. Superficial tumors (those not entering the muscle layer) can be "shaved off" using an electrocautery device attached to a cystoscope. Immunotherapy in the form of BCG instillation is also used to treat and prevent the recurrence of superficial tumors. BCG immunotherapy is effective in up to 2/3 of the cases at this stage. Instillations of chemotherapy into the bladder can also be used to treat superficial disease.

Untreated, superficial tumors may gradually begin to infiltrate the muscular wall of the bladder. Tumors that infiltrate the bladder require more radical surgery where part of the bladder or the entire bladder is removed and the urinary stream is diverted. In some cases, skilled surgeons can create a substitute bladder from a segment of intestinal tissue, but this largely depends upon patient preference, renal function, and the site of the disease.

A combination of radiation and chemotherapy can also be used to treat invasive disease.

Prevention

With no known cause for bladder cancer, it is not possible to prevent it. However, because certain lifestyle choices increase the risk of getting the disease, one may reduce their chances of coming down with bladder cancer by:

  • Not smoking
  • Following proper safety procedures when working with chemicals
  • Drinking plenty of water
  • Eating at least 5 servings of fruits and vegetables every day
  • Exercising regularly