Receiver operating characteristic analysis showed minimal improvement in the area under the curve (AUC) when PSA velocity was added to other predictors of prostate cancer risk (AUC 0.702 versus AUC 0.709).
Even less improvement in predictive accuracy was observed for detection of high-grade or clinically significant cancers.
"There was little evidence that PSA velocity adds an important level of predictive accuracy to either standard predictors or to PSA alone," the authors wrote.
"Superior risk stratification can be achieved simply by choosing a different PSA cut point, especially for the endpoints of high-grade cancer or clinically significant cancer," they added.
The Prostate Cancer Prevention Trial used a PSA cutoff of 4.0 ng/mL as a biopsy trigger, resulting in a biopsy rate of approximately one in 20 with no appreciable loss in diagnostic accuracy, Siu-Long Yao, PhD, and Grace L. Lu-Yao, PhD, of the University of Medicine and Dentistry of New Jersey, wrote in an accompanying editorial.
The study by Vickers et al. serves as a reminder that "the use of PSA as a screening tool leaves much to be desired," wrote Yao and Lu-Yao. "Indeed, after more than 20 years of PSA screening, it has been estimated that approximately one million men may have been unnecessarily treated for clinically insignificant prostate cancer."
"The shortcomings of PSA testing also remind us that there is still much art to the diagnosis and treatment of prostate cancer."