The Prostate Debate
Is the PSA test the best way to diagnose prostate cancer?
One in six men will get prostate cancer. But a wealth of information, and new research about the PSA test, have clouded the topic for many men.
Joseph P. Imperato, MD, FACR, a board-certified radiation oncologist at Northwestern Lake Forest Hospital, explains why prostate testing is still the right decision—but a very personal one.
Q: What exactly is the PSA screening test, and why is it used?
A: The prostate is a small gland that is part of the male sexual reproductive system. At about age 40, the prostate can start to enlarge and develop disease. The PSA blood test measures a protein produced by prostate cells called prostate-specific antigen.
PSA is actually not a great screening test for prostate cancer—a normal value does not mean you are free of cancer, and a high value does not mean you do have cancer. However, PSA can alert the doctor that there may be a prostate problem, and this can be further evaluated with a biopsy.
Q: Major new studies found that the PSA test saves few lives, which generated debate about the value of the test. What is your opinion?
A: It is a very valuable test, but not if used randomly or in isolation. The key is to look at test results over time, in a meaningful context. For example, if you take a PSA test every year for three years, and then the fourth year your levels double, that is very valuable information. Most of the people I diagnose with prostate cancer have a series of rising levels.
Q: If the PSA test is valuable, why did the studies show such poor results?
A: There were two studies: an American study and a European study. The American study found no great difference in death rates with or without a PSA test. The problem is that they could not keep the untested men—the control group—from getting tested elsewhere.
In contrast, the European test was well controlled because they had a greater ability to prevent testing for the control group. They found a 20 percent difference in the death rate for those who were tested. If you’re one of the men who were tested, that is a very good thing.
Q: Why does so much depend on the individual man?
A: Prostate cancer is the “ultimate” in personal health decision-making. This is because it can take up to 10 years between diagnosis and actually causing harm. The disease also has different grades and stages, and each of these behave differently. Some may never harm you; others are lethal even with aggressive treatment.
You need to consider life expectancy and the man’s current life situation: for example, what’s happening with his career and family? Is he managing another, more immediate health problem? What is the grade and stage of the cancer? Every step requires speaking with the physician about pros and cons. It is a disease that involves a lot of communication.
Q: What is the prognosis and treatment?
A: The majority of men diagnosed with prostate cancer have a mid-grade cancer that is amenable to treatment. Cure rates are nearly 90 percent, and the vast majority of those not cured will not die from the disease.
Men who have one isolated area of cancer may be treated with Focal Therapy, which is directed at the single location, not the whole prostate. For men with very low-grade, low-stage disease, we may recommend a "watch-and-wait" program: we test on a quarterly basis and if PSA levels change, we can discuss treatment options.
However, when the disease is high-grade and/or high-volume, it is more difficult. We may pursue aggressive treatment using radiation therapy, proton therapy or surgery. It is important to keep in mind that prostate cancer is still the second biggest cancer killer in men.
Q: Are there other aspects of the disease that you wish were better understood?
A: Medicine's biggest challenge is helping patients gain an accurate perspective on the disease. There is so much information available now, but most of it is read out of context. If patients think they have a high-grade cancer, they assume it is a disaster. When they read about low-grade prostate cancers, they mistakenly think it is a trivial disease.
Again—grade, stage, PSA velocity [how rapidly the results change] and an individual's health and age. That is why treatment options are often discussed using a team approach, with the urologist and radiation oncologist working together to determine the best treatment option for each individual.
Q: When, and how often, should men get the PSA test?
A: African-American men should get tested once a year beginning at age 40. Caucasian men should get tested starting at age 50—sooner if they have a brother or father with the disease. Some men also ask when they can stop getting tested, but the answer is tricky. Life expectancy and age are a factor, but people are living longer. Again, it is an individual decision that you should discuss with your doctor.