Prostate-Specific Antigen (PSA) Velocity of Change Is Not a Good Indicator for Biopsy in the Absence of Other Risk Factors Says New Research

© 2011 Peter Free

 

26 February 2011

 

 

PSA screening is not what it was once cracked up to be

 

PSA screening, in the absence of risk factors, has been an ambiguously useful tool.

 

Nor have I been convinced that recommending biopsies, simply because low PSA levels began noticeably changing upward (“velocity"), was a medically wise idea.

 

There are physical and psychological risks associated with biopsies.  Doing them when it is unnecessary, or only very marginally necessary, seems questionable.

 

Two days ago, new research added a sliver of scientific evidence to support my doubt.

 

The abstract of a comparatively large study of the control group involved in the Prostrate Cancer Prevention Trial reported that:

 

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).

 

Methods

 

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.

 

Results

 

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.

 

Conclusions

 

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.

 

© 2011 Andrew J. Vickers, Cathee Till, Catherine M. Tangen, Hans Lilja and Ian M. Thompson, An Empirical Evaluation of Guidelines on Prostate-specific Antigen Velocity in Prostate Cancer Detection, Journal of the National Cancer Institute, doi: 10.1093/jnci/djr028 (advance online publication, 24 February 2011) (paragraphs split)

 

Memorial Sloan-Kettering Cancer Center’s press release said, in part:

 

According to Peter T. Scardino, MD, Chair of the Department of Surgery, "This study should change practice. We have previously published papers determining that PSA naturally varies from month to month and have urged men whose PSA suddenly rises to wait six weeks and repeat the test before agreeing to a needle biopsy.

 

“This new study in a large population of men provides even stronger evidence that using changes in PSA as a basis for recommendation for biopsy leads to many more unnecessary biopsies and does not help to find the more aggressive cancers that we want to find and treat."

 

Dr. Scardino added that "men should be cautious before rushing into a biopsy for minor variations in their PSA level."

 

© 2011 Department of Public Affairs, Screening for PSA Velocity Leads to Many Unnecessary Biopsies and Should Be Removed from Screening, Memorial Sloan-Kettering Cancer Center (24 February 2011) (paragraph split)

 

 

Medicine is not as simple as we would like

 

Most recent research indicates that variable, multi-factorial complexity is characteristic of biological systems.

 

It is unlikely that convenient, generalized markers (like PSA) are going to be effectively applicable across normally-distributed populations.