PSA Test Linked to Better Prostate Cancer Survival
Study Shows That Some Men With Prostate Cancer Live Longer
Aug. 23, 2012 -- Despite the controversy surrounding its use, routine PSA prostate cancer screening may improve survival among men with spreading prostate cancer.
According to a new study, men diagnosed and treated for prostate cancer during the time when PSA screening was widely recommended lived longer than men who were diagnosed and treated before the "PSA era."
Researchers led by Ian M. Thompson Jr., MD, the director of the Cancer Therapy & Research Center at The University of Texas Health Science Center at San Antonio, analyzed data from three large studies starting in the mid-1980s and spanning through the PSA era, which began in 1990.
Specifically, men lived for about 49 months after being diagnosed with metastatic prostate cancer (cancer that had spread to other parts of the body) during the PSA era. By contrast, such men lived about 30 and 33 months before routine PSA testing was performed. The study did not look at men with prostate cancer that hadn’t spread.
African-American men are at greater risk for prostate cancer than white men, and they tend to fare worse. The advent of PSA screening may have also helped to improve the survival gap between African-American and white men with prostate cancer. Before the PSA era, African-American men lived for an average of 27 months after diagnosis. Their survival rate had increased to 48 months during the PSA era, the study shows.
The findings appear in the Journal of Urology.
PSA Testing Boosts Survival
Still, the PSA test is likely not solely responsible for these improvements. More detailed imaging and better treatments also likely play a role in these survival gains. “While not all of these welcome improvements can be attributed strictly to PSA testing, without a doubt it has played a role in extending many lives,” Thompson says in a news release.
PSA testing is controversial. A government task force recently recommended against such screening, but other groups take a softer stance. The American Cancer Society and others state that men should not get a PSA test until they discuss their personal risks and benefits with their doctor.
Otis Brawley, MD, chief science officer at the American Cancer Society, says the survival benefit seen in the new study is likely due to factors other than routine PSA screening.
Changes in imaging technology that better categorize prostate cancers and improved use of drugs also affect survival, he says. As to whether men should or shouldn't get PSA testing, there is no clear-cut answer. "Men need to be informed of the risks and benefits and make a decision."
The Argument Against Routine PSA Testing
There are some issues clouding blanket PSA testing, Brawley says. For starters, many men with prostate cancer will not need treatment because the tumors are slow growing. "Men with high PSA levels may end up with more testing and unnecessary treatment," he says. These treatments, including biopsy, are not without risks.
"The bottom line is that it is not 'should they or should they not' get the test. There is uncertainty. It's a huge question mark," Brawley says.
Brian M. Rivers, PhD, MPH, says more targeted screening may be the way to go. He is a researcher at Moffitt Cancer Center in Tampa, Fla. "We need to really target our PSA screening efforts to high-risk groups, not global screening," he says. Men who are at high risk for prostate cancer include those with a strong family history and African-Americans.
A man at high risk for prostate cancer with an abnormal PSA may be more likely to have an aggressive cancer than a man at low risk, he says.
"Have the conversation to see if PSA testing is right for you," Rivers says. "These findings point to the need for men to engage in shared decision making with their health care provider."