Study: Prostate Screening Saves Lives
PSA Tests Cut Metastatic Prostate Cancer by 35%
July 8, 2005 -- The PSA prostate cancer screening test saves lives, a new
For men with no symptoms of prostate trouble, PSA screening cuts the risk of
deadly metastatic prostate cancer -- cancer that spreads through the body -- by
The finding comes from a study comparing 236 men with metastatic prostate
cancer with 462 age-matched men without metastatic cancer. University of
Toronto researcher Vivek Goel, MD, and colleagues report the findings in the
August issue of The Journal of Urology.
"If this is the benefit PSA testing provides, it is going to warrant the
risks involved for most men," Goel tells WebMD. "In young men with no
risk factors, PSA testing may not be indicated, even at this level of benefit.
For men over 50, I think it will be. And for younger men with a family history
of prostate cancer or other risk factors, it will be indicated."
PSA -- prostate specific antigen -- is a chemical marker made only by cells
of the walnut-sized prostate gland. The first sign of prostate cancer can be a
spike in blood levels of PSA. A regular PSA test can detect early prostate
But the test is controversial. Low PSA levels don't necessarily mean a man
is cancer-free. And high PSA levels don't necessarily mean a man has dangerous
prostate cancer. Nevertheless, many American men get regular PSA tests -- which
go hand in glove with digital rectal exams -- to screen for early prostate
Unfortunately, PSA test results remain a matter of interpretation. Doctors
tend to refer men for prostate biopsy if they have a PSA score of 4 or more.
But that cutoff is arbitrary -- and not particularly meaningful, says Charles
A. Coltman Jr., MD, associate chairman for cancer control and prevention of the
Southwest Oncology Group in San Antonio.
In this week's issue of The Journal of the American Medical
Association, Coltman and colleagues reported the results of a study of
some 8,600 men who underwent PSA testing. All the men in the study agreed to
have a prostate biopsy -- whether or not they had a high PSA score.
"It was astonishing," Coltman says. "We found individuals with
prostate cancer at every range of PSA --from 4 down to 0.1. And a substantial
number of them had high-grade prostate cancer. In fact, some of these cancers
were in men who had gone through seven years of PSA and digital rectal exams
and were found to be normal in all respects."
What's a Man to Do?
The American Cancer Society recommends that men over 50 -- or high-risk men
over 45 -- discuss with their doctors whether they should begin annual PSA
tests and digital rectal exams. Men at high risk include blacks and those with
a family history of prostate cancer. Men at especially high risk -- those with
multiple first-degree relatives who have prostate cancer -- may wish to begin
this conversation even earlier, at age 40.