(NaturalNews) Since the prostate antigen screening test (PSA) began being widely used about 23 years ago, doctors have lauded its ability to detect prostate cancer at a very early stage. In fact, PSA testing has resulted in over a million additional men being diagnosed and treated for prostate cancer. The problem is, according to new research just published online in the Journal of the National Cancer Institute
, most of these cases were overdiagnosed and subjected men to treatment they didn't need.
For their study, H. Gilbert Welch, M.D., MPH, of the White River Junction VA and the Dartmouth Institute for Health Policy and Clinical Practice., and Peter C. Albertsen, M.D., of the University of Connecticut, studied data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program. They looked at age-specific prostate cancer incidence rates to investigate whether there was an excess or a deficit in the number of American men diagnosed and treated for prostate cancer after PSA screening was introduced in l987.
The results were clear. The researchers found that an additional 1.3 million men, especially younger men, had been diagnosed with the malignancy who would never have been found to have prostate cancer without the PSA test. And over one million of these men have been treated since l986.
So why isn't this good news if cancers are being found and treated earlier? Because over a million of these men who were told they had prostate cancer
most likely had no real health problem -- until they started down the path of side-effect laden treatments and became labeled as "cancer patients"."Given the considerable time that has passed since PSA screening began, most of this excess incidence must represent overdiagnosis," the authors of the study wrote. "All overdiagnosed patients are needlessly exposed to the hassle factors of obtaining treatment, the financial implications of the diagnosis, and the anxieties associated with becoming a cancer patient."
Even more importantly, as Otis W. Brawley, M.D., chief medical officer of the American Cancer Society, pointed out in an editorial accompanying the study, there has been little evidence that PSA screening has saved lives. All it has done is surge the rate of diagnosed prostate cancers upward. Moreover, Dr. Brawley warned that the highly marketed early-detection message has pushed public opinion toward accepting PSA screening as critically important and necessary for men -- when there's a lack of good science to back up that belief.
"Prostate cancer screening has resulted in substantial overdiagnosis and in unnecessary treatment. It may have saved relatively few lives. Results from this article and recent results from prostate cancer
screening and prevention trials demand reflection about what we as a society have done and are doing. Lessons to be learned have ethical and economic implications and involve our lack of respect for the scientific process and scientific evidence," Dr. Brawley wrote.
Another new study adds even more evidence that prostate cancer is being overdiagnosed and over treated. According to research just published in the Journal of Clinical Oncology
, many prostate cancer patients, including older men and men with small, low-risk tumors, can safely defer treatment for many years with no adverse consequences at all.
"With the advent of PSA screening nearly 20 years ago, we started to detect prostate cancers at much earlier stages," researcher Martin Sanda, MD, Director of the Prostate
Cancer Center at Beth Israel Deaconess Medical Center (BIDMC) and associate professor of surgery at Harvard Medical School, said in a statement to the media.
"Consequently, while PSA testing has enabled us to successfully begin aggressive treatment of high-risk cancers at an earlier stage, it has also resulted in the diagnosis of cancers that are so small they pose no near-term danger and possibly no long-term danger."
Dr. Sanda, along with colleagues from Brigham and Women's Hospital, the Harvard School of Public Health and the University of California, San Francisco, studied data from the Health Professionals Follow-Up Study, a large cohort study comprising 51,529 men who have been followed since 1986. Every two years, the participants respond to questionnaires and list information about diseases and health-related topics, including whether they've been told they have prostate cancer.
In all, 3,331 men reported receiving a diagnosis of prostate cancer between 1986 and 2007. Among this group, about ten percent (342 men) decided to put off having any treatment for one year or longer. Ten to 15 years later, 50 percent of these men who had initially deferred treatment still had not undergone any prostate cancer treatment.
To find out how this group of men fared in the long-term, the scientists looked at the data after an average of eight years after their initial diagnosis and then compared it with information provided by prostate cancer patients who had decided on going ahead with aggressive treatment, including surgery, radiotherapy or hormonal therapy.
"We found that the deaths attributed to prostate cancer were very low among the men with low-risk tumors," Dr. Sanda stated. "Our analysis showed that only two percent of the men who deferred treatment eventually died of the disease, compared with one percent of the men who began treatment immediately following their diagnosis. This is not a statistically significant difference."
According to the press statement, the researchers found that men diagnosed with low-risk tumors who deferred treatment were still doing fine an average of eight years and up to 20 years after their cancer diagnosis.
"Only half of these men wound up undergoing any treatment 10 to 15 years post-diagnosis. This means that they were able to avoid the disruption in their quality of life which might have occurred had they undergone immediate treatment," Dr. Sanda explained in the media statement.For more information:http://jnci.oxfordjournals.org/cgi/content/abstract/djp278http://jnci.oxfordjournals.org/cgi/content/full/djp310http://www.bidmc.org/News/InResearch/2009/August/Watchfulwaiting.aspx
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