There is not enough evidence to support routine screening tests for bladder cancer, according to new U.S. recommendations.
Several urine tests can detect bladder cancer, a disease that will kill an estimated 15,000 Americans this year. The tests are usually reserved for people with possible symptoms of bladder cancer—and not for screening symptom-free people.
And that is as it should be, according to the new recommendations, issued by the U.S. Preventive Services Task Force (USPSTF), an expert panel with federal government support.
There is no evidence yet that looking for bladder cancer in people who have no symptoms of it will cut death rates from the disease, the task force says.
And it's not clear that any benefits of routine screening would outweigh the risks, which include false-positive results that lead to needless invasive testing, costs and anxiety.
"This is an area where we just don't have much evidence," said Dr. David Grossman, a member of the USPSTF panel and a senior investigator at Group Health Research Institute in Seattle.
"We need to know a lot more about the potential benefits versus the risks," Grossman told Reuters Health.
Among the questions on bladder cancer screening are such big ones as, how accurate are urine tests in people without symptoms of the cancer?
Research suggests that the tests may have a high rate of false-positive results—in other words, they can mistakenly say a person has bladder cancer. That may lead to an unnecessary invasive procedure that carries some risk of complications—like perforation of the bladder, bleeding or infection.
It's also unclear whether treating early bladder tumors detected by screening actually saves lives, according to the USPSTF.
And that, Grossman said, is the "key most important question."
"The issue isn't detecting cancer. It's bladder cancer deaths that we care about," he said.
One of the problems is that screening for bladder cancer could pick up "trivial lesions" that would never have done any harm, Grossman explained.
Treating those tumors would not lengthen a person's life, but could cause side effects. Surgery to remove a small tumor can, like invasive tests, perforate the bladder or cause internal bleeding.
And as it stands, even without routine screening, the majority of bladder cancers are still confined to the lining of the bladder when they are diagnosed.
At that point, the disease is highly curable, with a five-year survival rate of 88 percent or higher, according to the American Cancer Society.
Bladder tumors that do reach underlying muscle, or spread beyond the bladder, have a worse prognosis. But there's no way to tell from current urine tests which tumors are likely to be aggressive and spread, according to the USPSTF.
All that said, bladder cancer screening is still an individual decision, Grossman said. Someone at high risk of the cancer, because he is a smoker with a family history of the disease, for example, might want to discuss screening with his doctor.
But even then, Grossman said, that person should be aware of the limits and risks of screening.
If people want to lower their odds of dying from bladder cancer, then the best move may be to quit smoking, or preferably never start.
"Smoking is an important cause of bladder cancer," Grossman said. "And we do have evidence of benefits from stopping smoking."
He also stressed that, by definition, screening refers to testing people who are symptom-free. People with possible symptoms of bladder cancer, such as blood in the urine, or frequent or painful urination, should talk with their doctor.