PSA blood test predicts risk of death from prostate cancer
23 Sept 2010
The PSA blood test commonly used to test for prostate cancer
can accurately predict the risk that a 60 year old man will die from
prostate cancer within the next 25 years.
The findings, by researchers at Memorial Sloan-Kettering Cancer
Center, in New York, and Lund University, in Sweden, are published
in the British Medical Journal.
The results could have important implications for determining which
men should be screened after the age of 60 and which may not benefit
substantially from continued prostate cancer screening.
The study analyzed blood samples from 1,167 men born in 1921 that
were collected between 1981 and 1982 as part of the Malmö Preventive
Project in Sweden. All men were carefully followed until they had
reached age 85 or had died.
After studying various biomarkers, the researchers found that the
PSA level was a highly accurate predictor of long-term risk. PSA
testing has been recommended for the early detection of prostate
cancer for many years; however this new data suggests a baseline PSA
could determine who should and should not continue to be screened
for prostate cancer.
“We were hoping to find a novel marker,” said lead researchers
Andrew Vickers, PhD and Hans Lilja, MD PhD. “What we found instead
was a new way of using an old test.”
According to the study, 126 men were diagnosed with prostate
cancer, and of those, 90% of deaths occurred in men in the top 25
percent of PSA levels at age 60. The researchers concluded that men
with a PSA level above 2 ng/ml at age 60 should be considered at
increased risk of aggressive prostate cancer and should continue to
be screened regularly.
Men with a PSA level below 1 ng / ml had a 0.2% chance of death
from prostate cancer. The researchers concluded that men with PSA
levels in this range, which is about half of all men, should be
considered at low risk of prostate cancer death and may not need to
be screened in the future. The study also indicated that some men
found to be at low risk may actually have prostate cancer; however
it is not likely to cause symptoms or shorten their life by the age
“This is a key finding,” said Dr. Vickers. “We know that
screening detects many prostate cancers that are not harmful,
leading to anxiety and unnecessary treatment. It is our ability to
determine the risk of the really aggressive cancers that makes this
approach of such great potential value.”