Prostate-specific antigen velocity not such a good indicator for prostate biopsy and cancer detection

Many practitioners have used PSA velocity (the rate at which prostate-specific antigen values increase) as an important indicator to gauge the risk of aggressive prostate cancer and weigh the decision to proceed to biopsy. A study just published in the Journal of the National Cancer Institute reveals that PSA velocity is not a reliable indicator and can lead to many needless interventions. The authors state their intention to examine pre-existing assumptions about the significance of the rate of PSA change:

"The National Comprehensive Cancer Network and American Urological Association guidelines on early detection of prostate cancer recommend biopsy on the basis of high prostate-specific antigen (PSA) velocity, even in the absence of other indications such as an elevated PSA or a positive digital rectal exam (DRE)...To evaluate the current guideline, we compared the area under the curve of a multivariable model for prostate cancer including age, PSA, DRE, family history, and prior biopsy, with and without PSA velocity, in 5519 men undergoing biopsy, regardless of clinical indication, in the control arm of the Prostate Cancer Prevention Trial. We also evaluated the clinical implications of using PSA velocity cut points to determine biopsy in men with low PSA and negative DRE in terms of additional cancers found and unnecessary biopsies conducted. All statistical tests were two-sided."

The current guideline based on an unproven assumption was clearly contradicted by their data:

"Incorporation of PSA velocity led to a very small increase in area under the curve from 0.702 to 0.709. Improvements in predictive accuracy were smaller for the endpoints of high-grade cancer (Gleason score of 7 or greater) and clinically significant cancer (Epstein criteria). Biopsying men with high PSA velocity but no other indication would lead to a large number of additional biopsies, with close to one in seven men being biopsied."

The implication of these findings is starkly articulated in their conclusion:

"We found no evidence to support the recommendation that men with high PSA velocity should be biopsied in the absence of other indications; this measure should not be included in practice guidelines."

The authors of an accompanying editorial thoughtfully state:

"The results...suggest that using PSA velocity may not provide more information to either physician or patient as we try to come to a decision about interpreting the results of any screening...The studies by Zeliadt et al. and Vickers et al. help us refine and focus our clinical approach, but they also remind us that the use of PSA as a screening tool still leaves much to be desired. Indeed, after more than 20 years of PSA screening, it has been estimated that approximately 1 million men may have been unnecessarily treated for clinically insignificant prostate cancer."