BY MARK SCHOLZ, MD
The Limitations of PSA
PSA is nonspecific. Meaning it doesn’t distinguish between the harmless, low-grade type of prostate cancer that can be watched and the higher-grade form that needs treatment. Therefore, urologists recommend a random, 12-core needle biopsy for practically everyone reporting an elevated PSA. One million men are biopsied annually when they do not need to be.
Once “cancer” is diagnosed, regardless of whether it is low or high grade, patients and doctors alike tend to assume radical treatment is required. Fear, lack of understanding, and over-enthusiasm for a quick solution leads to unnecessary treatment in over 50,000 men annually, even though studies prove that for many men active surveillance is perfectly safe.
Other Problems with Random Biopsy
Not only are random biopsies unpleasant, they can also be dangerous. Hospitalization for life-threatening infection due to random biopsy is a major risk, some men even die. Random biopsy has also shown a low but genuine risk of impotence.
Scanning Rather than Biopsy
Prostate scanning with multiparametric MRI detects high-grade prostate cancer better than random biopsy and is far less dangerous. If high-grade disease is detected by a scan, a targeted biopsy (limited number of cores aimed directly at the lesion) is recommended. In addition, modern scans are relatively “blind” to low-grade disease, sparing men unnecessary grief, eliminating random biopsies, and curtailing the risk of over-treatment.
Some Men Don’t Even Need a Scan
Recently, new tests have become available to help men with an elevated PSA avoid random biopsies and unnecessary treatment. These blood and urine tests can estimate the risk of high-grade prostate cancer. The blood test is called OPKO 4Kscore and the urine test is called SelectMDX. The likelihood of high-grade prostate cancer is reported as a percentage. Men whose percentages are very low can forgo MRI (and biopsy) if the risk of high-grade disease is less than five to ten percent.
Interpreting PSA Sensibly
PSA is frequently elevated due to causes unrelated to cancer. One such cause is an over-sized gland. Everyone should know the “Ten to One” rule. PSA averages one-tenth of the prostate’s size in normal men. For example, the average PSA for a 30cc prostate is 3, five for a 50cc prostate and 10 for a 100cc gland. PSA is only “abnormal” if it’s 50% higher than expected. For example, abnormal PSA for a 30cc prostate is above 4.5. For a 50cc prostate, abnormal is above 7.5. Other causes of high PSA include low-grade infections, lab variations, and recent sexual activity. These PSA fluctuations are usually temporary. With periodic retesting, levels decline spontaneously.
PSA testing saves lives and can’t be abandoned. If PSA is high, the first step is to confirm it by retesting. The second step is blood and urine testing. If these indicate a risk for high-grade disease, the next step is to scan with multiparametric MRI or color Doppler at a center of excellence. The last step, if the scans shows a suspicious lesion, is a targeted biopsy. Targeted biopsy means fewer cores and increased accuracy. Random biopsies are only appropriate for men without access to a center that performs high-quality scanning.