Men More Likely to Get Prostate Cancer Biopsy Following High PSA Test Result
According to research from the National Cancer Institute (NCI),
part of the National Institutes of Health, men who receive a reproducible
prostate specific antigen (PSA) test result of 7 ng/ml (nanograms
per milliliter) or greater are more likely to have a subsequent
prostate biopsy compared to men with lower but still abnormal test
results. Men with a positive digital rectal exam (DRE) without
a positive PSA test were less likely to receive biopsy than men
with a positive PSA test. This research appears in the March 2005
Journal of Urology*.
National data on prostate biopsy rates following PSA or DRE
screening are currently limited. These new findings, which contribute
a good deal of information on the subject, are one of the initial
results from the prostate component of NCI's ongoing multicenter
Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening
Trial. The PLCO is testing whether screening with PSA and DRE
decreases prostate cancer mortality in men age 55 to 74.
Men in the screening arm of this randomized trial undergo PSA
testing and DRE upon entry. They then have these tests annually
for the next three years, and then have a PSA test without a
DRE in years 4 and 5. This study looked at all men who had a
positive PSA or DRE upon entry and men with positive post-entry
results occurring by December 2000.
A total of 4,801 out of close to 40,000 men who were originally
randomized to the screening arm of the PLCO had one abnormal
prostate screening test upon entry, of whom 2,717 had abnormal
PSAs. Diagnostic procedures, including biopsy, were looked at
for a 3-year period following the first positive screening. Diagnostic
follow-up in the United States was done at many sites across
the country** and thus occurred beyond the control of the PLCO.
However, the entry screening PSA test was done by one central
laboratory at the University of California Los Angeles. The pattern
of biopsies in PLCO men is thought to be representative of current
clinical practice in response to a positive PSA or DRE in the
years 1993 to 2001.
The results of a PSA test or DRE had a substantial impact on
- Men with PSAs greater than 4 ng/ml (considered positive in
this study) upon entry into the PLCO had a biopsy rate over a
3-year period of 64 percent, while those with a positive DRE
and PSA of 4ng/ml or less had a 27 percent biopsy rate.
- Men with a baseline PSA greater than 10 ng/ml had a greater biopsy rate (85
percent) after 3 years than did men with baseline PSAs of 4 to 7 ng/ml (58
- Among men first becoming PSA positive (greater than 4 ng/ml) after the study
entry screen, those with PSA levels greater than 10 ng/ml were not more likely
to receive a biopsy than men with PSAs of 4 to 7 ng/ml.
The study authors were able to identify various factors that
affected biopsy rates:
- Prior prostate biopsy, prior PSA tests, and a history of
prostate problems were significantly associated with a lower
biopsy rate only in men whose PSA was positive at entry.
- In men with a positive DRE and negative PSA, a PSA value of 2.5 to 4.0 was
associated with an increased biopsy rate compared to a result lower than 2.5.
- Among men with a PSA test greater than 4, men with a positive DRE were about
twice as likely to receive biopsy as men with a negative DRE.
- Men often got repeat PSAs after the screening PSA. Those with repeat PSAs
below 4 ng/ml had much lower biopsy rates than men with repeat PSAs greater
The men in this study and their physicians were aware that they
were participating in a clinical trial and this fact may have
affected their behavior in terms of diagnostic follow-up and
biopsy. Nevertheless, the results of this study should be useful
for calculating the cost of screening and for modeling how DRE
and PSA tests are used in the general population.
According to lead author Paul F. Pinsky, Ph.D., NCI, "We
can not yet answer the question of whether PSA tests and DRE
have an effect on overall prostate cancer mortality, but these
interim results give us a good indication that biopsy is more
likely following a screening PSA of 7 ng/ml or greater that is
reproducible in a large, geographically diverse sample of American
men. These results suggest that PLCO is evaluating the effects
of screening in a current and vigorous manner."
For more information about cancer, visit the NCI Web site at
http://www.cancer.gov or call NCI's Cancer Information Service
at 1-800-4-CANCER (1-800-422-6237).
* Pinsky, PF, Andriole, GL, et al. Prostate Biopsy Following
a Positive Screen in the Prostate, Lung, Colorectal and Ovarian
Cancer Screening Trial. Journal of Urology, Vol. 173, March 2005.
** The ten PLCO Screening Centers nationwide include: the University
of Colorado, Denver, Colo.; Georgetown University Medical Center,
Washington, DC; Pacific Health Research Institute, Honolulu,
Hawaii; Henry Ford Health System, Detroit, Mich.; University
of Minnesota, Minneapolis, Minn.; Washington University, St.
Louis, Mo.; University of Pittsburgh, Pittsburgh, Pa.; University
of Utah, Salt Lake City, Utah; Marshfield Medical Research and
Education Foundation, Marshfield, Wis.; and University of Alabama