New Method Measures More Reliable Cancer Marker

If you’re over 50 and you have a prostate, you’ve certainly heard of the PSA blood test for prostate cancer… and if not, talk to your doctor — it’s time for a screening. While often criticized, this “prostate-specific antigen” test, in combination with a digital rectal exam and an evaluation of your family’s history with the disease, is currently the best-available screening method for prostate cancer, which is the second most common type of cancer in men, after skin cancer.

Now, I don’t want to minimize the importance of a PSA test, but it does have a few faults — some people with cancer have low PSA levels and may go undiagnosed based on PSA alone and some people with high PSA levels don’t have cancer, since other problems (i.e., prostatitis, urinary tract infection) can elevate PSA. And PSA levels vary among men with prostate cancer. That’s why the PSA test is used primarily to send up a red flag — it’s one of the pieces of information your doctor uses to judge if you require a prostate biopsy, a tissue sample from your prostate to determine conclusively if you have prostate cancer. Many doctors now believe, in fact, that it is the relative percentage of change in PSA over time, called PSA velocity, which may more accurately predict the presence of cancer, in addition to providing valuable prognostic information for men who have been diagnosed with cancer. All in all, it’s a system that works but is far from ideal. However, a test currently in development may help change that.


Developed by urologists at Johns Hopkins University’s Brady Urological Institute, the early prostate cancer antigen-2 (or EPCA-2) test looks for the presence of proteins that are only found in prostate cancer cells, instead of for a protein produced by all prostate cells, as the PSA test does. While much more research needs to be done to confirm these results and their clinical utility, early testing has shown the new test to be incredibly specific — efficient not only at detecting prostate cancer with a low (3%) rate of false positives, but also able to gauge whether the cancer is confined to the prostate or has spread.

That’s important, according to Ganesh Palapattu, MD, assistant professor of urology at the University of Rochester Medical Center, because it can impact the course of treatment. If the cancer is thought to be aggressive, then more potent treatment measures can be called on to combat the disease. But if the cancer appears to be less aggressive and is confined to the prostate, other approaches such as “active surveillance” might be sufficient, depending on the circumstances.

“More men die with prostate cancer than of it,” says Dr. Palapattu. “If we knew from the get-go whether or not a patient had a more aggressive form of the disease, we could identify those who would really benefit from aggressive therapies and not subject the patients who don’t need it to all their toxicities and side effects.”


Unfortunately, because this new test is still in the early stages of development and it may yet prove unreliable in prospective studies, it could be two or more years before (or if) it is approved for widespread use. According to Dr. Palapattu, the best strategy for men worried about prostate health is to discuss concerns with their primary care physician, get screened, and perhaps schedule an appointment with a urologist.

In the meantime, says Dr. Palapattu, you may be reassured to learn that the leading cause of death among all patients with prostate cancer is… heart disease. “The vast majority of men with prostate cancer possess generally slow-growing and non-aggressive disease,” he says, while also noting that prostate cancer is responsible for approximately 30,000 deaths in the US annually. It’s best to avoid it or catch it early… and that’s why, for now, men over 50 need to keep getting checked.