Just a few milliliters of blood are sufficient to test men for a special protein produced exclusively by the prostate. If the value of the so-called prostate-specific antigen (PSA) has increased, it can indicate the presence of a tumor in the prostate. However, further investigations are necessary to confirm a suspicion for cancer. "In combination with the ultrasound examination of the prostate and the palpation of the organ, the PSA test is considered to be the most important instrument in the early detection of prostate cancer since its introduction in the 1980s," says Dr. Stephan Neubauer, Urologist at the West German Prostate Center in Cologne. "In the course of the urological screening, which is recommended for men aged 45 years, a large number of prostate carcinomas have been discovered in an early and thus curable stage", emphasizes the Cologne Urologist.
There have been controversial discussions for several years whether a PSA determination actually leads to a reduction in mortality caused by prostate cancer. The main reason for doubting the significance of the PSA test was most of all the results of a large-scale American study on PSA screening (PLCO-Studie1) in more than 76000 patients. There was no survival benefit for the men who were regularly subjected to a PSA test compared to the control group, for which the PSA value was not determined over the entire seven-year study period. Supposedly, as a recent reevaluation of the investigation has shown2, the study shows a fatal error, since a large part of the men in the control group underwent a PSA test on their own initiative.
A mistake with far-reaching consequences
"This is a giant scandal," says Dr. Neubauer, pointing out the consequences of this fatal error. After the sobering result of the US study, increasingly more reservations were raised regarding the effectiveness of routine PSA screening, which were then reflected in recommendations from public institutions. Not only were men in the US recommended to refrain from PSA testing, but also reports in the German Media resulted in fewer patients undergoing PSA screening in Germany. Dr. Neubauer emphasizes, "to forego PSA testing has fatal consequences only becoming apparent in the future". Thus, extrapolations predict that foregoing PSA testing during urological screening could cost the life of about 60 000 American men by 2025.
With more than 60 000 new cases per year, prostate cancer is the most frequently diagnosed cancer in males. According to the Robert Koch Institute, with a mortality rate of more than 12 000 deaths per year, prostate cancer is still the third leading cause of premature death. "The new findings prove once again that the PSA test is still the most important instrument for the early detection of prostate cancer," summarizes Dr. Neubauer. "Otherwise, men with an aggressively growing tumor that without an appropriate therapy would lead to a premature death will be deprived of preventive treatments.”
PSA screening can save lives
However, as with any early detection study, the PSA test also carries the risk of an "over-therapy". In some cases, tumors are treated that would never have led to death. „The most important is to find the right way to handle the results," says the Cologne Urologist. Neubauer criticizes that although the interdisciplinary guideline for the early detection, diagnosis and therapy of prostate cancer gives clear recommendations as to when and under what circumstances the test should be administered, PSA levels are sometimes still misinterpreted, which may lead to premature treatment measures. Thus, a biopsy is frequently done based on a short-term elevated PSA value, instead of first observing the increasing vs. decreasing of the PSA level.
The prostate specialist also demands a different handling of tumors detected by PSA testing, Neubauer continues, "It cannot be that a patient with an elevated PSA value automatically lands on the operating table," says the prostate specialist. Especially the radical prostate surgery, which is still the most frequent treatment in Germany, is partly associated with a high incontinence and impotence rate. In men who have a low risk prostate carcinoma, it is often sufficient to closely monitor the tumor (Active Surveillance). "If treatment becomes necessary,” emphasizes the Cologne Urologist, “the focus should be on achieving optimal healing rates with minimal side effects. Today, modern forms of brachytherapy and radiotherapy are generally much more successful than surgery. In any case, each patient affected should obtain at least one second opinion before deciding to have the organ removed".
Shoag JE1, Mittal S1, Hu JC2. Reevaluating PSA Testing Rates in the PLCO Trial. N Engl J Med. 2016 May 5;374(18):1795-6. doi: 10.1056/NEJMc1515131.