Let's Talk About Bladder Cancer Causes

Here’s a stat you probably didn’t know: One in 40 people will get bladder cancer at some point during their lives. What you probably want to know is whether there’s any way to predict if that one in 40 will be... you. Among the many challenges of bladder cancer is the fact that it’s hard to know who will get it. Scientists are still a way from developing a genetic test for it. That said, there are several well-known risk factors—and understanding what they are can help you take action if you ever develop symptoms of the disease.

What Is Bladder Cancer Again?

It’s the sixth most common cancer in the U.S., and it accounts for about 3% of all new cancer cases. About 2.4% men and women will develop bladder cancer in their lifetime, and this year the National Cancer Institute estimates that there will be 81,000 new cases. It’s more common in men than women—and way more common in people over age 55, with most of those cases diagnosed in people between the ages of 65 to 84.

Bladder cancer starts the same way in men and women, though. Cells mutate, then grow quickly, eventually forming tumors. Most of the time, these tumors grow in the first layer of the bladder wall, called the inner lining (they're known as non-invasive tumors). Sometimes, though, the cancer becomes more aggressive and spreads deeper into the bladder tissue; about 4% of the time, it metastasizes to other parts of your body like your lungs.

How far and even whether your tumor will spread depends on a host of factors. What’s important to know is that bladder cancer is treatable—there are new drugs and procedures that weren’t available two years ago that have improved the quality of life for people who are diagnoed. The percentage of all bladder cancer patients who are still alive after five years is 77%, and that includes those whose cancer was advanced.

So What Causes Bladder Cancer?

No one knows what triggers the cells in your bladder to go rogue. But if you think about it, the bladder is pretty susceptible to cancer-causing chemicals, which slosh around in the urine that’s stored there. Over years, these chemicals can cause mutations in the cell’s DNA. We all have the ability to repair these DNA mutations, and we usually do. But when we can’t, through some combination of genetics, unhealthy habits, and random bad luck, these cells can become cancerous.

There are number of factors that can affect your risk of getting bladder cancer, including lifestyle and exposure to certain chemicals. Here are some of the common ones.

Smoking Definitely Ups Your Chances of Bladder Cancer

One of the biggest risk factors for bladder cancer is smoking, or living with someone who does. About 50% of all bladder cancer cases occur in smokers or former smokers, according to one study by the National Institutes of Health.

Current smokers are four times more likely to develop the most common type of bladder cancer (known as urothelial or transitional cell carcinoma or TCC) as nonsmokers—and they are more likely to have their tumors return. The more you smoke, the higher your risk. And the odds of bladder cancer increase by 22% for people who are constantly exposed to secondhand smoke.

That’s because there are about 30 to 40 known chemicals in cigarette smoke that are specifically linked to TCC, including arsenic. Why would cancer-causing chemicals you inhale get to your bladder in the first place? It’s actually a pretty straight path: After your lungs absorb these chemicals, they enter the bloodstream and go into your kidneys, which filters them and dumps them in the form of pee into your bladder and the entire urinary tract.

Quitting helps your odds—researchers discovered that post-menopausal women who’d kicked the habit 10 years earlier had cut their risk by 25%. Avoid vaping to help you do that, though. While the research is still in its earliest stages and being done in mice, scientists have found evidence to suggest that e-cigarette smoke containing nicotine can lead to genetic changes in the bladder that make it more likely cells will multiply and become cancerous.

Other Chemicals Play a Role in Causing Bladder Cancer

Aromatic amines, chemical byproducts used in making dyes, leather goods, and textiles, are another risk factor. Aromatic amines are also found in plastics, diesel exhaust, and paints (as well as cigarette smoke).

People who work around these chemicals, including house painters, machine and metal workers, truckers, and mechanics, have roughly double the risk of developing bladder cancer. So do firefighters, thanks to their exposure to these and other cancer-causing chemicals that are released in the air when buildings catch fires and they take off their respirators after the fire has been put out.

Arsenic, which is naturally found in groundwater, can raise the risk of bladder cancer by 40% if it exceeds 10 micrograms per 1.06 ounces of water. Most water systems don’t contain arsenic.

The danger comes when people get their water from wells, as is the case in New England (where the rates of bladder cancer are higher than average) as well as other parts of the country. If that’s where your H2O comes from, install a water filter designed to screen out arsenic, like the Zero Water pitcher, which did the trick according to a study published in Environmental Research.

Bladder Cancer Can Run in Families, Too

Well, maybe. Italian researchers found that bladder cancer risk doubled if you had a parent or sibling (first-degree relatives) with the disease, and it went up four times if you were a smoker as well. If a first-degree relative has any type of cancer your risk goes up 32%, according to a study done on Spanish bladder cancer patients.

Bladder cancer experts think that it’s less likely that there are specific bladder-cancer causing genes running in families. More likely, relatives inherit a sensitivity to some types of cancer-causing chemicals, making it harder for them to fix cells as they divide and change into cancerous ones.

Age Also Increases Your Chances

About 90% of bladder cancers are diagnosed in people over 55, and nearly two-thirds of those cases are diagnosed in people ages 65 to 84. The probable reason: It takes decades for chemicals or chronic infections to change the DNA of the cells in your bladder so that they can mutate, spin out of control, and form tumors.

Your Gender and Ethnicity Are Another Risk Factor

Men are more than four times as likely to get bladder cancer than women, especially white men and women. Over their lifetime, men of all races have a 1 in 27 chance compared to a woman’s 1 in 89. One theory why men are particularly susceptible: androgen receptors, which men have more of than women. These receptors help the body respond to testosterone and other hormones, by, say, controlling sex drive or hair growth. But they can also spur tumor growth, too, especially in prostate cancer.

Still, even though women have lower odds of developing bladder cancer, they tend to be diagnosed when the cancer is more advanced and have higher death rates, as do African-American men and women.

Why the discrepancy among women (both white and black)?

Partly it has to do with anatomy—women’s bladder walls are thinner, making it easier for a tumor to grow into the muscle tissue, where cancer is harder to treat. But it’s also because doctors tend to dismiss symptoms, like blood in the urine, as urinary tract infections, postponing a diagnosis until much later.

African-American men also die at higher rates than whites. Their tumors tend to be more aggressive, though no one knows why, but in general blacks have less access to good care—from specialists and cancer centers—along with not-so-great health insurance policies that make access to care harder.

UTIs Can Also Raise Your Risk of Bladder Cancer

So can having kidney stones, probably because chronic infections create inflammation, and there’s a link between inflammation and cancer. Another chronic condition that’s been associated with bladder cancer is type 2 diabetes, though only in men. People with diabetes tend to have more UTIs, so that could be the connection, as well as a faulty immune system thanks to the disease.

Since there’s no screening test for bladder cancer, you have to know the signs and symptoms of bladder cancer if you have any of these risk factors. One of the earliest signs is blood in the urine. If you see it, call your doctor so you can be checked out at once.