New evidence shows PSA screening does reduce the risk of death from prostate cancer

Micrograph showing the most common prostate cancer
A new study finds that PSA screening reduces prostate cancer mortality. (Image: Michael Bonert - CC BY-SA 3.0)

New research casts doubt on current guidelines that recommend men don’t undergo prostate-specific antigen (PSA)-based screening for prostate cancer.

The latest study, published this week in the Annals of Internal Medicine, finds that early screening lowers the risk for prostate cancer death by as much as 32% in men compared to those who were not screened. The results contradict the current advice of the U.S. Preventive Services Task Force, which recommends against routine PSA tests because the risks outweigh the benefits.  Those risks include overdiagnosis and unpleasant side effects, such as incontinence and impotence, from treatment.

Prostate cancer is the most common non-skin cancer among American men, according to the Centers for Disease Control and Prevention. However, the CDC states that prostate cancer usually grows slowly, and finding and treating the disease before symptoms occur may not improve a patient’s health or lifespan.

But that thinking, which is based on the results of two landmark clinical trials, may be flawed, according to the new research that reevaluated the previous trials using different mathematical models.

The new analysis, funded by the National Cancer Institute, assessed the differences between the 2009 European Randomized Study of Screening for Prostate Cancer (ERSPC) and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO), which offered conflicting results. The ERSPC showed a significant benefit to the early screening as it would reduce the risk of men dying from prostate cancer. However, the PLCO, found it would not reduce the risk.

The conflict, researchers now say, is that the PLCO trial itself had problems. Half of the 77,000 men ages 55 to 77 in the trial were told to have yearly PSA tests, the other half were not. However, nearly half of the men who were in the no-PSA group were receiving annual screenings as part of the routine care in their doctors’ offices. Therefore, it wasn’t a true comparison when the original researchers counted deaths in each group.

E. David Crawford

“When we accounted for the actual amount of screening received, the two trials have remarkably similar results," said E. David Crawford, M.D., a co-author of the study, and founder and chairman of the Prostate Conditions Education Council (PCEC). "Instead of comparing the screened and non-screened populations, we looked at the intensity of screening in each relative to no screening. The estimated common effect of screening suggests it can significantly reduce the risk for prostate cancer death."

Crawford spoke to FierceHealthcare this week about the findings, which he said is timely given that prostate cancer awareness week will occur later this month and the U.S. Preventive Services Task Force is expected to update its prostate cancer screening recommendations.

There is a benefit to the early screening, he said, because the new findings show a 25% to 32% improvement in survival rate. The PSA is a great first step he said, because it could signal treatment for those most at risk. New genomic tests can then reveal those patients who have the most significant risk for the disease.

Wendy L. Poage,

Wendy L. Poage, president of PCEC, said she hopes the new research will motivate physicians to encourage their male patients to get the PSA test.

“The negative talk about PSA screening has a lot of the time made men think it’s not important, but prostate cancer is the second leading cause of cancer for men,” she told FierceHealthcare. “A paper like this states that yes, there is a benefit to early detection that is significant, and we need to get the information out there. In general most cases are slow growing and that gives an opportunity to watch and wait, and you don’t have to treat immediately. But we can treat prostate cancer effectively when it’s diagnosed early and we can make it survivable. Not having testing or early detection or advanced treatment means we have less options for survivorship.”

In an accompanying opinion piece in the Annals of Internal Medicine, Andrew J. Vickers, Ph.D., from Memorial Sloan Kettering Cancer Center, said he hoped that the paper will put to rest the question of whether PSA screening reduces prostate cancer mortality. Instead, the discussion should focus on how to implement screening so that the benefit outweighs the harms of overdiagnosis and overtreatment.