Who should get the PSA test for prostate cancer?
Prostate cancer is the most common cancer found in American men, and the second leading cause of men's cancer deaths.
Given those rates, it would seem like a screening test that can catch the disease early would be a major boon to medical care. However, it hasn't been that simple.
In fact, “it’s one of the most controversial areas in medicine,” said Dr. Jon LaPook, chief medical correspondent for CBS News.
LaPook spoke with Dr. Herbert Lepor, the Martin Spatz Chairman of the department of urology at NYU Langone Medical Center in New York, to discuss the highly-debated prostate cancer test, the prostate-specific antigen (PSA) test. Lepor is the co-author of the book “Redefining Prostate Cancer.”
The PSA test is a blood test that looks for a specific protein that is only produced by the prostate. The higher the levels of PSA, the more likely the person has prostate cancer.
If someone is found to have an elevated level, they are often recommended to have a biopsy taken from their prostate. This involves inserting 12 needles into the prostate using an ultrasound and taking a random sampling of tissue.
“It seemed as though it would be the answer to help us identify earlier cancers,” Lepor explained.
Before the PSA test, being diagnosed with prostate cancer was almost a death sentence. Now, 16 percent of men are diagnosed, but only 3 percent succumb to the disease.
The problem is that the majority of tumors are not significant enough to warrant treatment. One study suggested that 40 percent of men who receive a positive test result have a cancer too slow-growing to be deadly. The biopsies, radiation, surgery and other treatments can cause serious side effects, including impotence, incontinence and other complications -- even death.
"Unlike pancreatic cancer or lung cancer, as the statistics show, many of these [prostate] cancers are not significant," Lepor said. "They would be best not diagnosed.”
That’s why an expert panel that advises the U.S. government on medical treatment guidelines, the U.S. Preventative Services Task Force, recommended against healthy, symptom-free men of any age getting the PSA test in May 2012 guidelines. Previously, men over the age of 75 were advised not to get the test.
However, some experts believe that the PSA test should still play a role. Without using the blood test, the only method left to check for
prostate cancers is a digital rectal exam, when a doctor checks the prostate
through the rectum using his or her fingers. Some tumors can be felt, but not others, and they
are often discovered too late.
Lepor said that what doctors need to is “screen smarter.” He suggested still using the PSA test and then repeating it to reconfirm if a high PSA score is detected. Then, Lepor said doctors could use an advanced MRI scan to try and locate the tumor, rather than going in blindly for a biopsy.
In some cases, Lepor said, a man might not need a biopsy unless their PSA scores keep increasing or they have significant family history. In other instances, the MRI could help guide doctors to get more accurate biopsies.
The goal, he explained, is to “identify those cancers that need to be diagnosed and need to be treated as opposed to all of those insignificant cancers that the current way we are doing things is leading to.”
