Most prostate cancers detected by screening aren’t dangerous in the first place
Only about one in 10 prostate cancers detected by screening actually poses a threat to a man’s life, according to a new analysis conducted by researchers from the University if Cambridge.
The findings come from a preliminary analysis of data from the ongoing Prostate Testing for Cancer and Treatment trial (ProtecT), funded by the United Kingdom’s Department of Health. Under ProtecT, approximately 250,000 men between the ages of 50 and 69 are undergoing prostate cancer screening and analysis. Only 10 percent of the men being screened had elevated levels of the prostate specific antigen (PSA), which is considered a marker of cancer risk.
ProtecT comes as the United Kingdom considers implementing a nationwide prostate cancer screening program. Yet because the majority of prostate cancers are slow-growing and may never pose a threat to a man’s life, growing numbers of medical professionals are questioning this plan.
Prostate cancer treatment can carry severe side effects, including impotence and incontinence.
Preliminary analysis of the ProtecT data shows that 25 percent of men with elevated PSA levels (roughly 2.5 percent of males in the study) had some form of prostate cancer. This means that if the United Kingdom implements population-wide screening, 160,000 cases of cancer will be detected each year, in comparison with the current 30,000.
Neal notes that this is what happened when PSA testing became widespread in the United States.
“There was an epidemic of prostate cancer in America,” he said. “The number of cases virtually tripled in five years.”
Yet the ProtecT data show that only 12 percent of detected prostate cancers had spread beyond the prostate gland, indicating a dangerous form of the disease.
“What we don’t want to do is to treat a man at 65 who is destined to die at 85 of a stroke,” researcher David E. Neal said.
Source: www.reuters.com