The Prostate Specific Antigen (PSA) test and its effectiveness in diagnosing prostate cancer

9/11/2012

The Prostate Specific Antigen (PSA) test and its effectiveness in diagnosing prostate cancer
By Thomas K. O’Neill, MD

What is PSA? It’s the prostate specific antigen, an enzyme produced by prostate cells that is measured by a blood test. PSA can be elevated due to prostate cancer, inflammation, and an enlarged prostate. If the PSA is elevated within a certain range there is about a 25% chance the biopsy will show cancer.

Screening with PSA has become controversial. There are some important facts everyone should know prior to deciding if they should be screened. A white man has a one in six chance of being diagnosed with prostate cancer. For an African-American man, the risk is one in three. More than 30,000 men die of prostate cancer each year. It is the 2nd leading cause of cancer death in men. It is estimated 241,740 men will be diagnosed with prostate cancer in 2012.


Since PSA has been used for screening there has been a 42% reduction of age adjusted deaths from prostate cancer. The best screening study done in Europe showed a 32% reduction in deaths from prostate cancer at 11-year follow-up in the screened group. Computer models show there will be increasing benefit with longer follow-up. It is clear PSA screening has resulted in a diagnosis at an earlier stage. This has resulted in saving many lives. 

Prostate cancer can be successfully treated when caught early. Prior to PSA screening, 33% of patients undergoing surgery had cancer that had spread beyond the prostate. Now with PSA screening, there has been a 75% reduction in proportion of men diagnosed with prostate cancer that had spread beyond the prostate. The test has drawbacks but when used appropriately it can help diagnose prostate cancer earlier and save lives.

The American Urological Association recommends PSA screening beginning at age 40. If elevated, the decision to have a biopsy should depend on PSA level, results of rectal exam, age, risk factors and overall health. Most urologists agree PSA screening can be stopped when the patient does not have a 10-year life expectancy. For now we should not abandon PSA screening. Until a better test is developed, it remains one of our most potent weapons against prostate cancer. If used correctly, it can help save thousands of lives.

Thomas O’Neill, MD is a board certified urologist with MountainCare Urology, practicing with board certified urologist Jerome Marchuk, MD and certified physician assistant Jane Girskis at MedWest-Harris. MountainCare Urology recently moved to the first floor of Harris Medical Park, 98 Doctors Drive, Sylva. MountainCare Urology sees patients in Bryson City at MedWest-Swain the first Friday of each month. Call 631-8755 or visit www.medwesthealth.org for more info.