Your bladder is a muscular, balloon-shaped organ located in your pelvis.
It stores urine that your kidneys produce during the process of
filtering your blood. Like a balloon, the bladder can get larger or
smaller depending on the amount of urine it holds. Urine passes from
each kidney into your bladder through a thin tube called a ureter and is
eliminated from your body through another narrow tube, the urethra. A
woman's urethra is relatively short, whereas a man's is longer, passing
through the prostate gland and ending at the tip of the penis.
How cancer develops
Healthy cells grow and divide in an orderly way. This process is
controlled by DNA — the genetic material that contains the instructions
for every chemical process in your body. When DNA is damaged, changes
occur in these instructions. One result is that cells may begin to grow
out of control and eventually form a tumor, a mass of malignant cells.
Most bladder cancers begin in the specialized cells that line the walls
of your bladder (transitional cells). The same type of cells occur in
your kidneys, ureters and urethra where they may also give rise to
malignant tumors. When chronically exposed to certain chemicals,
especially those in tobacco smoke and certain dyes, these cells can
Some cancers remain confined to the bladder lining (carcinoma in situ
— in one place). But other cancers are invasive, growing into or through
the bladder wall, and eventually into nearby lymph nodes and adjacent
organs. In time, cancer may spread (metastasize) to other organs,
including the lungs, liver or bones.
Just what causes
bladder cancer isn't entirely clear. Certain inherited
metabolic factors may play a role. People whose bodies metabolize toxic
chemicals quickly may be less susceptible to bladder cancer than people
who metabolize the same chemicals more slowly. Chief among these
chemicals are polycyclic hydrocarbons found in cigarettes and in some
Cigarettes, in fact, are the leading known cause of bladder cancer.
That's because cancer-causing chemicals (carcinogens) in tobacco can
become concentrated in your urine and eventually damage the lining of
Smokers are two to three times more likely to develop bladder cancer
than are nonsmokers. The risk is even greater for women. Cigarette for
cigarette, women have twice the risk of bladder cancer that men do.
Other known causes of bladder cancer include:
exposure to carcinogenic chemicals.
This is especially true of chemicals used in the oil, rubber, dye,
paint and textile industries. Experts estimate that at least 25
percent of all male bladder cancers result from occupational
exposure, even if that exposure was brief. Often, these cancers
develop many years later. Smokers who work with toxic chemicals are
at especially high risk of bladder cancer.
People living in areas where pesticides are widely used and the
drinking water contains high levels of arsenic are more likely to
develop bladder cancer. Although exactly what constitutes dangerous
levels of arsenic remains controversial, the risk of developing lung
and bladder cancer from arsenic appears higher than originally
Treatment with the anti-cancer drugs cyclophosphamide (Cytoxan) and
ifosfamide (IFEX) increases your risk of bladder cancer. If you're
treated with these drugs, your doctor is likely to prescribe another
medication, mesna, to help reduce bladder irritation.
In some parts of the developing world, especially Egypt, a chronic
parasitic infection (schistosomiasis) can lead to a type of bladder
cancer called squamous cell carcinoma. Both the infection and
squamous cell carcinoma are rare.
Use of the herb
This Chinese herb, which is included in some weight loss
supplements, has been linked to both bladder cancer and kidney
failure. A number of other factors have been suggested as possible
causes of bladder cancer, including:
These form when chlorine is added to drinking water. Although
there's no definitive proof of a link between chlorine by-products
and bladder cancer, research in this area is ongoing.
Early studies linking this artificial sweetener to bladder cancer in
mice caused the Food and Drug Administration (FDA) to ban cyclamate
in 1969. Subsequent studies haven't found as clear a connection.
Animal studies have shown a relationship between this artificial
sweetener and bladder cancer. But the connection between saccharin
and cancer in humans isn't clear. For now, products containing
saccharin carry a warning about a possible link to bladder cancer.
If you think you're at risk of bladder cancer, discuss your concerns
with your doctor. He or she may be able to suggest ways to reduce your
risk. Also, keep in mind that having one or more risk factors doesn't
mean you'll develop the disease. In general, the following factors may
increase the likelihood that you'll develop bladder cancer:
Smoking is the single greatest known cause of bladder cancer. The
risk increases with the number of cigarettes smoked a day and the
number of years you've smoked.
Repeated exposure to chemicals used in the manufacture of dyes,
rubber, leather, textiles and paint products may increase your risk
of developing bladder cancer years later.
The chance of getting bladder cancer increases as you grow older.
The average age at diagnosis is 68 or 69. People younger than 40
rarely get the disease.
Caucasians are twice as likely to develop bladder cancer as blacks
and Hispanics are. Asians have the lowest rates of the disease.
Men are two to three times more likely to get bladder cancer than
Treatment with certain anti-cancer drugs increases your risk of
Chronic or repeated urinary infections or inflammations may increase
your risk of a certain form of bladder cancer. But doctors don't
believe infection or inflammation alone causes cancer.
You're at higher risk of bladder cancer if you have family members
with the disease.
Having bladder cancer once makes it more likely you'll get it again.
Tumors may recur in your ureters or urethra as well as in the