Bladder Cancer Risk Factors

Many risk factors make a person more likely to develop bladder cancer.

What is a risk factor?

A risk factor is anything that raises your chance of getting a disease such as cancer. Different cancers have different risk factors. You can change some risk factors, like smoking. Others, like your age or family history, can’t be changed.

But having a risk factor, or even many, doesn’t mean that you will get the disease. Many people with risk factors never get bladder cancer, while others with this disease may have few or no known risk factors.

Still, it’s important to know about the risk factors for bladder cancer because there may be things you can do that might lower your risk of getting it. If you're at higher risk of bladder cancer because of certain factors, there might be things you can do that could help find it early, when treatment is most likely to be effective.

Smoking

Smoking is a major risk factor for bladder cancer. People who smoke are at least 3 times as likely to get bladder cancer as people who don't. Smoking causes about half of all bladder cancers.

If you or someone you know smokes and would like help quitting, see our Guide to Quitting Smoking, or call us at 1-800-227-2345 for more information.

Workplace exposures

Certain industrial chemicals have been linked with bladder cancer.

Chemicals called aromatic amines, such as benzidine and beta-naphthylamine, which are sometimes used in the dye industry, can cause bladder cancer. Workers in other industries that use certain organic chemicals also may have a higher risk of bladder cancer.

Industries carrying higher risks include makers of rubber, leather, textiles, and paint products, as well as printing companies.

Other workers with an increased risk of developing bladder cancer include painters, machinists, printers, firefighters, hairdressers (probably because of heavy exposure to hair dyes), and truck drivers (likely because of exposure to diesel fumes).

Cigarette smoking and workplace exposures can act together to cause bladder cancer. So, people who smoke and also work with cancer-causing chemicals have an especially high risk of bladder cancer.

Certain medicines or herbal supplements

Some research has suggested that the use of the diabetes medicine pioglitazone might be linked with an increased risk of bladder cancer. The risk seems to get higher when higher doses are used.

Dietary supplements containing aristolochic acid (mainly in herbs from the Aristolochia family) have been linked with an increased risk of urothelial cancers, including bladder cancer.

Arsenic in drinking water

Arsenic in drinking water has been linked with a higher risk of bladder cancer in some parts of the world. The chance of being exposed to arsenic depends on where you live and whether you get your water from a well or from a public water system that meets the standards for low arsenic content. For most Americans, drinking water isn't a major source of arsenic.

Not drinking enough fluids

People who drink a lot of fluids each day tend to have lower rates of bladder cancer. This might be because they empty their bladders more often, which could keep chemicals from lingering in their bladder.

Race and ethnicity

White people are about twice as likely to develop bladder cancer as African American and Hispanic people. Asian American people have slightly lower rates of bladder cancer. The reasons for these differences are not well understood.

Older age

The risk of bladder cancer increases with age. About 9 out of 10 people with bladder cancer are older than 55.

Being born male

Bladder cancer is more common in men than in women.

Chronic bladder irritation and infections

Urinary infections, kidney and bladder stones, bladder catheters left in place a long time, and other causes of chronic (ongoing) bladder irritation have been linked to bladder cancer (especially squamous cell carcinoma of the bladder). But it’s not clear if they cause bladder cancer.

Schistosomiasis (also known as bilharziasis), an infection with a parasitic worm that can get into the bladder, is also a risk factor for bladder cancer. In countries where this parasite is common (mainly in Africa and the Middle East), squamous cell cancers of the bladder are much more common. This infection is an extremely rare cause of bladder cancer in the United States.

Personal history of bladder or other urothelial cancer

Urothelial carcinomas can sometimes start in different areas in the bladder, as well as in the lining of the kidney, the ureters, and urethra. Having cancer in the lining of any part of the urinary tract puts you at higher risk of having another cancer, either in the same spot as before, or in another part of the urinary tract. This is true even when the first tumor is removed completely.

For this reason, people who have had bladder cancer (or other urothelial cancers) need careful follow-up to look for new cancers.

Bladder birth defects

Before birth, there's a connection between the belly button and the bladder. This is called the urachus. If part of this connection remains after birth, it could develop into cancer. Cancers that start in the urachus are usually adenocarcinomas, which are made up of cancerous gland cells. Some adenocarcinomas of the bladder start here. But this is still rare, accounting for less than 1% of all bladder cancers.

Another rare birth defect called exstrophy greatly increases a person’s risk of bladder cancer. In bladder exstrophy, both the bladder and the abdominal wall in front of the bladder don’t close completely during fetal development and are fused together. This leaves the inner lining of the bladder exposed outside the body. Surgery soon after birth can close the bladder and abdominal wall (and repair other related defects), but people who have this still have a higher risk for urinary infections and bladder cancer.

Genetics and family history

People who have family members with bladder cancer have a higher risk of getting it themselves. Sometimes this may be because the family members are exposed to the same cancer-causing chemicals (like those in tobacco smoke). They may also share changes in some genes (like GSTM1 and NAT2) that make it hard for their bodies to break down certain toxins, which can make them more likely to get bladder cancer.

A small number of people inherit a gene syndrome that increases their risk for bladder cancer. For example:

• A mutation of the retinoblastoma (RB1) gene can cause cancer of the eye in infants, and also increases the risk of bladder cancer.
• Cowden disease, caused by mutations in the PTEN gene, is linked mainly to cancers of the breast and thyroid. People with this disease also have a higher risk of bladder cancer.
• Lynch syndrome (also known as hereditary non-polyposis colorectal cancer, or HNPCC) is linked mainly to colon and endometrial cancer. People with this syndrome might also have an increased risk of bladder cancer, as well as other cancers of the urinary tract.

For information on testing for inherited gene changes that increase cancer risk, see Understanding Genetic Testing for Cancer Risk.

Chemotherapy or radiation therapy

Taking the chemotherapy drug cyclophosphamide for a long time can irritate the bladder and increase the risk of bladder cancer. Those taking this drug are often told to drink plenty of fluids to help protect the bladder from irritation.

People who get radiation to the pelvis to treat other types of cancer are more likely to develop bladder cancer.