Three new studies support the use of PSA testing for prostate cancer, putting to rest the idea that the test does not save lives.
I want to make sure that all men know about new reports that contradict previous studies about the use of the prostate-specific antigen (PSA) tests for prostate cancer. Two were presented in March 2018 at the European Association of Urologists Congress and one was released in September 2017 by the Annals of Internal Medicine.
That earlier report of September 2017 found that men between 55 and 70 benefit from getting the PSA test, which can result in a longer life. The two March 2018 reports by researchers at the University of California, Irvine found an increase in more serious prostate cancer cases since the 2012 recommendation by the U.S. Preventive Services Task Force (USPSTF) that men between the ages of 55 to 69 not be screened for PSA unless they were at elevated risk for prostate cancer.
The September 2017 study, which was completed by Dr. Alexender Tsodikov and his colleagues, reviewed data from the Prostate, Lung, Colorectal and Ovarian Cancer Screening (PLCO) trial and the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial. These trials have been reviewed in the past, but this analysis found important differences in the studies. Once they accounted for the dissimilarities, a conclusion was made that PSA testing can lower a man’s risk of prostate cancer death by 25 to 32 percent.
In one of the CU, Irvine studies, Dr. Thomas Ahlering and colleagues analyzed 19,602 men at nine high-volume referral centers in the United States. They compared prostate cancer patients with a Gleason grade 8 or higher and who had seminal vesicle and lymph node involvement before the 2012 USPSTF recommendations were issued with such patients after the recommendations were issued. They noted a 22.6 percent decrease in surgical volume after the recommendations, as well as an increase in median PSA level from 5. ng/mL prior to the recommendations to a median of 5.8 ng/mL after the USPSTF non-screening recommendations.
“Treating high-risk disease has its limitations, because you are not going to cure the majority of patients no matter what you do, so the better answer is to diagnose prostate cancer earlier,” Ahlering told Medscape Medical News. “If our data are correct, the most important thing to do is to start screening more intensely again.”
A related UC, Irvine study by Linda Huynh analyzed data from 1,380,219 men who had undergone radical prostatectomy in one of three time periods assessed, two before and one after the USPSTF 2012 recommendation to reduce screening. The study found that after the 2012 recommendations, the risk in absolute numbers of high-risk prostate tumors with Gleason scores of 8-10 increased in stepwise fashion, while each year saw more cases of high-grade disease.
These studies are welcome news for all of us at Urology Associates, because we have been unflagging champions of PSA testing throughout a long period of controversy.
The history of PSA testing
Doctors have been suggesting men be tested annually for prostate cancer with the use of the PSA test since the 1980s. Testing for prostate cancer is complicated since the tumor tends to grow slowly. Because of this, testing is much different than for diseases like breast cancer where you can easily find the tumor. The PSA blood test has been found the most effective way to detect early signs of prostate cancer.
Once a PSA test is complete, a biopsy might be needed to confirm the findings of the blood test. While this is a comparatively safe procedure, it still carries possible complications like infection. Due to the possible complications and because for most men prostate cancer is not fatal, some doctors in the United States started to view the PSA test as unnecessary.
In 2012, the U.S. Preventive Services Task Force (USPSTF) announced its recommendation that men between the ages of 55 and 69 not get a PSA test unless they have a family history of the disease or are at heightened risk of prostate cancer.
The task force made its conclusions based on two studies published in 2009 from the PLCO in the U.S. and the ERSPC. The U.S. study did not find a difference in deaths caused by prostate cancer in men who were screened with a PSA and those who were not. The European study discovered that PSA tests led to a 21 percent lower risk of prostate cancer being the cause of death during the study compared with those who did not get screened.
Given the uncertainty with these two studies, one finding a reduction in deaths and one seeing no change, the USPSTF stated the data was not convincing enough to recommend men receive a PSA test.
New review, new findings
In Dr. Tsodikov’s September 2017 study, a new team looked at the same data from the PLCO and ERSPC and found that PSA testing does, in fact, reduce the deaths from prostate cancer. Their findings were different from the previous analysis because they found the studies had major differences that made comparing the two like comparing apples and oranges. Once you set up parameters to account for the differences, it was clear that getting a PSA test was the correct recommendation for men between 55 and 70.
When looking at the two studies, you could find that the doctors in the U.S. trial were using a greater threshold for PSA levels for completing a biopsy compared with the European trial. This could have led to men in Europe getting treated sooner, which one could tie to a reduction in prostate-related deaths.
Another jarring difference was that the PLCO study was screening men every year, while the men in the ERSPC were only screened every two to four years.
A final major difference to point out is that prior to the U.S. study, PSA screenings were seen as the norm and many of the men in the control group had a PSA test at least once before. This caused the nontested group to be an inaccurate group to compare the data against.
Taking these differences into consideration, the September 2017 study found that men who get the test can see a 20 to 32 percent decrease in prostate cancer deaths compared with men who are not screened. The two more recent UC, Irvine studies corroborate the earlier one and add more detail and import to the argument for more, not less, PSA screening.
In 2017 the USPSTF updated its recommendations for men to make an individual decision on getting the test. Since these studies have been released the USPSTF has not revised their guidelines for screening for prostate cancer, but I feel that the change will be coming soon.
In the meantime, hopefully these latest studies give men the clarity and confidence needed to ask for a PSA test annually. We are more than happy to oblige.