Dear Dr. Motola:
What is the normal PSA for a 69 year-old man? At what level does the PSA become troubling or warrant further tests?
PSA cut off levels have been debated for many years. Traditionally the cut off for a normal PSA has been 4, however more recently age-adjusted PSA values are being advocated. Utilizing age-adjusted PSA values helps to explain that the PSA of a 45-year-old should be different than that of a 70-year-old. A PSA less than 3.5 is usually considered normal for men age 55 or younger. Similarly as patients get into their mid 70s, higher values of PSA are now being accepted without the need for the patient to undergo biopsy.
Rather than utilizing the absolute PSA value, the rate of change of the PSA is a very important variable. PSAs that are rising at a very rapid rate are more like to be associated with prostate cancer. A PSA increase of more than 0.75 per year may also be indicative of underlying prostate cancer. Furthermore, abnormal rectal examinations need to be evaluated with a prostate biopsy.
Once it is determined that your PSA is abnormal, the next step would be a transrectal ultrasound guided biopsy of the prostate, which will help determine if there is underlying prostate cancer.