(NaturalNews) Regular prostate cancer screening has no effect on the risk of death from the disease, according to a large-scale, long-term study conducted by researchers from the National Cancer Institute and published online in the New England Journal of Medicine.
The prostate specific antigen (PSA) test, which measures blood levels of a protein produced by the prostate gland, has been controversial as a cancer screening test since it first became popular in the 1990s. At the time, Brawley was one of many scientists who raised concern over the usefulness of the test.
"I can say firsthand that some American screening advocates were vicious in their attacks on those who dared question prostate cancer screening," Brawley said. Some lay and physician advocates had a religious-like fervor for screening."
In the current study, part of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, researchers looked at rates of prostate cancer and prostate cancer death among 76,693 men, half of whom were assigned to undergo PSA screening once per year. The other participants were assigned to continue with regular health care practices and not advised regarding prostate screening. The participants were then followed for seven to 10 years each.
The current results are considered preliminary and the study is still ongoing. By its conclusion, all participants will have been followed for 13 years each.
In the preliminary analysis, the overall rate of prostate cancer death among participants "was very low and did not differ significantly between the two study groups," the researchers wrote. An independent review committee has endorsed the findings and recommended their publication.
Because most prostate cancers are slow growing, many men may die of other causes without ever experiencing symptoms from an active cancer. Neither the PSA test nor a biopsy, however, is able to determine whether a cancer is slow-growing or aggressive.
The U.S. Preventive Services Task Force has recommended against prostate cancer screening in men above the age of 74.