Leonard S. Marks, M.D.

1st Quarter, 2000 - Baltimore, MD (February 22, 2000)---A "Best Practice Policy" for use of PSA testing was issued by the American Urological Association (AUA) today. The policy, which was developed by a multidisciplinary panel of 8 and peer reviewed by 47 experts from urology, internal medicine, gerontology, oncology, and radiation therapy, appears to establish major guidelines for the foreseeable future. The entire policy was published in the February issue of Oncology and is publicly available online free at http://www.cancernetwork.com. Measuring blood levels of PSA (prostate specific antigen) is now the commonest means of detecting prostate cancer. The diagnosis must be subsequently established by biopsy, since the PSA test is not specific for cancer. According to Ian Thompson, M.D., the chairman of the panel of experts, the new policy report distills available data about PSA "…down to a short, easy to digest balanced document on what we know about the subject relating to the diagnosis, staging, and management of prostate cancer." Of all prostate cancers currently detected, approximately 75% are associated with an abnormal PSA test.

Regarding early detection of prostate cancer, the expert panel concluded that routine PSA testing shoudl be offered in men when:

• Male Cancer Incidence in U.S.

  Age is 50 years and greater, unless the man has increased risk factors, such as genetic predisposition via family history or African-American racial status. In these "at risk" men, PSA testing should be offered between 40 - 50 years of age.
• AND life expectancy is at least 10 years.
• AND should be performed in conjunction with the digital rectal exam (DRE), since the combination of the two tests is more sensitive for diagnosis than either one alone.

Regarding prostate biopsy, the panel concluded that this is indicated when:

• PSA is 4.0 ng/ml or greater.
• PSA has increased substantially from one test to the next. An increase of 0.75 ng/ml or more between two annual tests appears to be reason for concern.
• DRE is abnormal. Since approximately 25% of prostate cancers are associated with PSA levels below 4.0 ng/ml, the DRE is also very important.

Regarding use of PSA testing in the staging of men with known prostate cancer, the experts concluded:

• Men with PSA levels below 10 ng/ml are most likely to have localized disease and respond well to local therapy (radical prostatectomy or radiation therapy).
• Routine bone scans are generally not required for men with clinically localized prostate cancer when their PSA is < 20 ng/mL.
• CAT scans and MRI scans are generally not indicated if the PSA level is less than 25 ng/ml.
• Pelvic lymph node dissection is probably not necessary if PSA level is less than 10 ng/ml or if PSA is less than 20 ng/ml AND the Gleason score is < 6.

Regarding use of PSA testing in the follow-up of men after treatment for prostate cancer, the panel members determined the following:

• Periodic PSA testing should follow any form of treatment for prostate cancer, since PSA levels can indicate need for further treatment.
• Following curative radical prostatectomy, PSA levels should become undetectable.
• Following curative radiation therapy, PSA levels should fall to very low levels, probably < 0.5 ng/ml, and should not rise on any successive tests. The nadir value is not reached for a median of 17 months.
• The pattern of PSA rise after local therapy for prostate cancer can help distinguish between local recurrence and distant spread. Biochemical recurrence (PSA) occurring > 24 months after local treatment and who have a PSA doubling time >12 months are likely to have local recurrence. Others are like likely to have distant spread.
• Following androgen deprivation therapy, men who experience a PSA decrease of more than 90% from baseline (or undetectable levels) at 3 and 6 months are likely to have a prolonged progression-free survival.
• Following secondary treatment in men with hormone-refractory prostate cancer, a decrease in PSA levels of 50% or more after 8 weeks indicates improved survival in response to the new treatment.

The PSA test was first brought to market in 1986 by Hybritech, Inc., which is now a division of Beckman Coulter, Inc. Additional sources of PSA information are available online at the following websites:

Explanation of Free PSA Testing

Selected USRF publications relating to PSA:

• "Serum prostate specific antigen levels after transurethral resection of prostate"
  
  
• "Influence of finasteride on free and total serum prostate specific antigen levels in men with benign prostatic hyperplasia."
  
  
• "A precursor form of prostate specific antigen is more highly elevated in prostate cancer compared with benign transition zone prostate tissue."
  
  

American Cancer Society
statement on early detection of prostate cancer.

AUA Patient Education brochure:
Prostate Cancer Awareness for Men.