Change in PSA levels over time is a more accurate predictor of aggressive prostate cancer
As a rule, the higher the PSA (prostate specific antigen) level in the blood, the more likely a prostate problem is present. However, factors such as age, race, and noncancerous conditions can affect PSA levels. A recent study showed evaluating PSA measurements taken over time improves the accuracy of aggressive prostate cancer detection compared with a single measurement of PSA.
Aside from nonmelanoma skin cancer, prostate cancer is the most common cancer among men in the United States, and the second most common cause of cancer death, according to the CDC. In 2008, prostate cancer was diagnosed in nearly 215,000 men in the United States and more than 28,000 men died from the disease.
The retrospective study examined the electronic health records of nearly 220,000 men 45 years and older over a 10-year period who had at least one PSA measurement and no previous diagnosis of prostate cancer. The study found that annual percentage changes in PSA more accurately predicted the presence of aggressive prostate cancer when compared to single measurements of PSA alone, but only marginally improved the prediction of prostate cancer overall.
“The use of a single, elevated PSA level to screen for prostate cancer is considered controversial given the questionable benefits of PSA screening on prostate cancer mortality. The screening may also result in unnecessary prostate biopsies and subsequent treatments for localized prostate cancer, as it does not distinguish well between slow-growing and aggressive disease,” said Lauren P. Wallner, PhD, MPH, lead author of the study and postdoctoral research fellow at Kaiser Permanente Southern California. “Our study demonstrates that repeated measurements of PSA over time could provide a more accurate–and much needed–detection strategy for aggressive forms of prostate cancer.”
Men in the study were also found to experience a 2.9% change in PSA levels per year on average and that the rate of change in PSA increased modestly with age.
“The results of this study could provide clinicians with a better prostate cancer preventive strategy that could help differentiate between men with an aggressive form of the disease and those who have slow-growing, indolent cancer that may not necessarily merit treatment,” said Wallner. “While we do not suggest that patients proactively seek out additional PSA measurements, men who already have had multiple PSAs may consider discussing the change in their PSA levels with their clinician when determining future treatment strategies.”
The PSA test measures the level of prostate specific antigen, a substance made by the prostate, in a man's blood. It is one of the most commonly used tests to screen for prostate cancer, according to the Centers for Disease Control and Prevention.
This study was published in the British Journal of Urology International (2013; doi:10.1111/j.1464-410X.2012.11651.x).