About a dozen new medical tests are coming to market that aim to more accurately diagnose prostate cancer and go well beyond the standard PSA (prostate-specific antigen) blood screenings used today. Several of them may even allow men to forego getting a biopsy that more than 1 million men diagnosed with prostate cancer undergo each year. That's because these new tests will help doctors distinguish between aggressive disease and slow-growing tumors.
For men entering the latter half of their lives, a diagnosis of prostate cancer can be frightening. About 30 million men are screened for prostate cancer each year, according to the Centers for Disease Control and Prevention. Of that number, more than 180,000 will be diagnosed annually, and a smaller subset — 26,000 — will die of the disease, said the Prostate Cancer Foundation.
While the name evokes consternation for good reason, deciding whether to treat or not treat prostate cancer can be maddening. Sometimes the risk of undergoing surgery to remove a prostate, or radiation to fight the cancer, can be greater than the risk of actually dying from prostate cancer itself — especially if it's not an aggressive form of prostate cancer.
Statistics tell the story. Some 60,000 men with low-risk cancers will undergo surgery or radiation, according to medical experts.
"Prostate cancer is totally different and unique from any other cancer out there," said urologist Jeremy Lieb, who practices at Pacific Urology in Walnut Creek, California, and has 14 years of experience. "For every 100 men, only 3 percent will die of the disease. The real challenge is determining which patients are that 3 percent."
Now urologists are turning to new tests developed by medical scientists and companies to get more precise diagnoses. By testing samples of blood and urine or analyzing the genetic makeup of prostate cells for changes in their DNA, urologists are trying to more accurately determine not only if men have prostate cancer but also if those diagnosed have aggressive cancer that calls for further treatment or indolent, low-grade prostate cancer that poses very little risk.
Almost 100 percent of prostate cancer cases are curable, and among the biopsies performed annually, only about one-quarter show cancer in the prostate. For men with prostate cancer who undergo radiation or surgery to remove the prostate gland, the side effects can be onerous and include incontinence and infection.
(Source: Prostate Cancer Foundation)
The challenge is in separating the patients with aggressive cancers that need immediate treatment from the patients with lower-risk cancers that can be monitored at annual check-ups. This is why urologists are paying attention to new tests.
"All of these tests are focused on helping us pick out who has indolent cancer that we can keep an eye on and who has aggressive cancer and can risk the side effects from treatment and surgery," said Phillip M. Pierorazio, urologist and faculty member at the James Buchanan Brady Urological Institute at Johns Hopkins Hospital.
The new tests — using blood, urine and tissue samples — go well beyond PSA tests and aim to tell men in advance, not just if they have prostate cancer but if it is aggressive enough to warrant treatment or if it can be safely monitored instead. While most have been validated in retrospective laboratory studies, only a few have been vetted by the Food and Drug Administration.
"We caution patients and doctors that no independent body has reviewed such tests to determine whether they are safe and effective," said one FDA spokeswoman in an email to CNBC.
A new urine test from Cambridge, Massachusetts-based Exosome Diagnostics looks at exosomes — messengers between cells that can help cancer travel. By reading the RNA inside exosomes associated with prostate cancer, the test can identify which prostate cancers are aggressive enough to warrant a biopsy and further treatment.
"The problem is, when a patient hears cancer, they want to be treated," said Tom McLain, COO of Exosome Diagnostics. "Another part of the challenge here is, urologists make a lot more money doing a biopsy than they would running another urine test."
Exosome Diagnostics' test launched this month in two phases. A more targeted launch in the New England area has made the test available to patients at several community urology practices. Simultaneously, a national study of 1,000 patients to continue gauging the test's effectiveness is being undertaken at large universities, including Columbia University and the Johns Hopkins University, as well as at large practices such as Delaware Valley Urology and the Walter Reed Medical Center. McLain said the company will soon seek FDA approval.
The 4Kscore, developed at New York's Memorial Sloan Kettering Cancer Center, is another new test that takes place before a biopsy even occurs. The 4Kscore analyzes PSA-related proteins pulled from blood samples and calculates the percentage that a biopsy would discover an aggressive prostate cancer. These percentages are expressed as Gleason scores: A score of 3 indicates a low-grade cancer, a 4 indicates a cancer of intermediate aggressiveness, and a score of 5 indicates a potentially aggressive prostate cancer, according to Dr. Lieb. Manufactured by OPKO Health, the 4Kscore became available in 2014 and costs about $1,000.
Traditional screening for prostate cancer usually begins with a blood test for PSA, a protein produced by the prostate gland. An elevated PSA level can indicate prostate cancer, and men with an elevated PSA have typically had biopsies done for further examination. When the FDA approved the PSA test in 1994 for routine screenings for prostate cancer in asymptomatic men, the results were staggering. Whereas roughly 70,000 men each year in the 1970s were diagnosed with prostate cancer, according to Dr. Lieb, by the early 2000s about 250,000 men were being diagnosed with prostate cancer.
But the number of men dying from prostate cancer remained roughly the same, at around 30,000 per year, and led to the concern that many men were having biopsies they didn't need or receiving prostate cancer treatment, in the form of surgery or radiation, that caused more harm than good.
In 2012 the U.S. Preventive Services Task Force recommended that men forego screening for prostate cancer. In 2013 the American Urological Association released new guidelines about PSA testing, concluding that the tests led to needless biopsies and overtreatment of prostate cancers that were not life threatening.
"In the PSA era, the death rate from prostate cancer went down 40 percent. Those of us in the field don't want to see the clock turn back … but we want to be more precise in our diagnosis," said Stuart Holden, medical director of the Prostate Cancer Foundation with more than 40 years' experience as a practicing urological oncologist.
For men who do undergo biopsies, several new tests aim to determine whether additional treatment is necessary.
The Prolaris from Myriad Genetics is a genetic test done on biopsied prostate tissue that helps identify whether a patient needs further treatment by predicting their risk of dying from prostate cancer over the next 10 years.
Others tests take place after a negative biopsy to check the area surrounding the prostate for tumors. ConfirmMDx from MDxHealth analyzes biopsied tissue for abnormal changes in the DNA of prostate cells. If those abnormal changes are there, the test will detect a "halo," the presence of which might mean the existence of prostate cancer that was missed in the initial biopsy. A urologist can order the test, but the analysis of a patient's biopsied prostate tissue actually happens in MDxHealth's laboratory in Irvine, California. Once completed, the results are sent back to the urologist.
How effective or reproducible these new tests are is still a question. As of right now, no test has been cleared or approved by the Food and Drug Administration for an intended use to explicitly rule out the need for a biopsy.
"It's hard to know as a practicing physician which tests to use," said Dr. Holden. "It's a rapidly moving field, and these tests haven't been compared head to head."
New tests also come with a big price tag. The Prolaris test, which Dr. Lieb uses in his practice, can cost between $3,000 and $4,000, although he says the test is Medicare-reimbursed and has an out-of-pocket cap of $375 for patients. The Exosome Diagnostics' test is list-priced at $595, although it's not reimbursable yet through Medicare or private insurers. The company said that will be a goal for 2017.
But the promise of these tests in helping more men survive prostate cancer, while avoiding unnecessary complications or discomfort, is huge, especially for patients who have a borderline aggressive form of prostate cancer and are on the fence about having aggressive treatment.
"What's the bottom line here? Prostate cancer is generally overtreated in America," said Dr. Lieb. "How are we going to reduce the amount of men who are overtreated? We're moving to educate men so they make the best decision."
— By Andrew Zaleski, special to CNBC.com