Prostate cancer is the commonest cancer in men. From them, 45 is recommended for regular screening. But this is not very useful palpation, said the German Cancer Research Center (DKFZ) in Heidelberg. “With this study only superficial tumors can be detected, which have already reached a certain size, which often means that the disease no longer is in an early stage.” The accuracy of the study was low.
For several years, doctors do know that prostate cancer increases the concentration of prostate-specific antibody (PSA) in blood. Would it not make sense to regularly for all older men to determine the PSA level in the blood?
So far there is no scientific evidence of a benefit of such screening. Two studies in Europe and the U.S. should answer this question. However, they come to different conclusions, reported that New England Journal of Medicine.
In the American study, nearly 77,000 men from 55 to 74 years were divided into two groups. One was an annual PSA screening offered in addition to palpation, 85 percent of the subjects made use of it. The other served as a control group. However, it was at 52 percent of them nevertheless reviewed the PSA value, since the trial in the U.S. is already standard. After seven years there was no significant difference in prostate cancer death rates in both groups, note the study authors.
In the European study data were analyzed by some 160,000 men 55 to 69 years from seven countries. Nearly half of them were offered a regular PSA blood test. In this screening group did 82 percent of the subjects at least once use of the trial.
The doctors registered in the entire group of fifth fewer deaths from prostate cancer than in the control group. , Prostate cancer screening can reduce deaths by 20 percent, “then announced to the European Society Urologists (EAU).
However, the study authors themselves point out that PSA testing led to their subjects too many abortions and have over diagnosis. Thus undergone more than three quarters of the men, which was measured by an elevated PSA level, unnecessarily tissue examination. Were also detected in a screening numerous little aggressive cancer that would probably never become a problem. Nearly one third of prostate cancer, according to information from the European Urologengesellschaft such indolent tumor. These cancers do not need to be treated.
The physician Michael Barry of Harvard University in Boston, commented in the New England Journal of Medicine, that the diagnosis was prostate cancer in the screening group with 820 cases per 10,000 subjects were almost twice as frequently as in the control group. As a result, it was 277 out of 10,000 men in the screening group, the prostate was removed completely in the control group at 100, Barry estimated. Radiotherapy with or without additional hormones had received about 220 out of 10,000 men in the screening group in the control group only 123.
Waste handling
“On one hand, which will save you extra life, 39, made redundant you treat,” said the Hamburg medical physicist Hans Hermann Dubber. He is known for critical statistical analysis of medical studies.
Because prostate cancer is a rare kind of death, it comes in spite of the large number of study participants to compare very small numbers of cases, Dubber writes in the Lancet Oncology. This resulted in a large statistical uncertainty. Thus, although the doctors registered a 20 percent lower prostate cancer mortality in the screening group. Because of statistical fluctuation, the difference could, however, somewhere between two and 35 percent.
“Both works are much too small for her question, and is by far,” he says. He also sees another major problem: With the usual screening trials should a potential benefit in a particular disease are documented, so as to reduce the mortality from prostate, the PSA screening. For statistical reasons, whether it is not possible to observe unknown side effects, because they were lost in the large number of total deaths.
Given the methodological difficulties, he concludes that the benefit or harm a prostate cancer screening are determined not realistic in the context of studies. Hans Hermann Dubber should “treat the sick, not healthy.”
Also, some scientists at the DKFZ criticize a prostate cancer screening. Set jointly with the University of Bremen and the general health fund (AOK) on the Internet a test available to serve any particular individual as a decision.
