PSA

Prostate specific antigen (PSA) is a glycoprotein produced by the epithelial cells of the prostate gland. It can be detected in the body with a simple blood test. Often, the PSA is elevated in processes that effect the prostate gland. One such process is prostate cancer and thus, PSA is used as a screening test for prostate cancer. However, it is very important to note that PSA is not one hundred percent accurate in detecting prostate cancer. A PSA may be normal in a man with prostate cancer or elevated in a man with no prostate cancer.

Conditions that may cause PSA elevation are prostatitis, benign prostatic hyperplasia, prostate infarct, prostate massage, prostate biopsy and ejaculation.

When a urologist sees a patient with an elevated PSA, he has to identify the cause. This begins with taking a focused urologic history from the patient. A physical examination is performed (including a digital rectal examination) and a urinalysis is obtained. The normal PSA range is 0 - 4.0 ng/cc. However, younger men typically have lower PSAs and age adjusted PSAs have been determined.

PSA AGE ADJUSTMENT GUIDELINES

Ages	PSA results
40-49	0 - 2.5
50-59	0 - 3.5
60-69	0 - 4.5
70 plus	0 - 6.5

Prostate Biopsy
If the age specific PSA is elevated and the history and physical do not suggest an obvious cause, an ultrasound-guided needle biopsy of the prostate is typically recommended. This is an office procedure which takes fifteen minutes to perform. An ultrasound probe is passed into the rectum and is used by the urologist to guide a small needle which can sample prostate tissue. The patient can resume his daily activities after the biopsy and the results can help determine if prostate cancer is present.

Free PSA
Free PSA is a method of making PSA more specific for prostate cancer and limiting biopsies which may be unnecessary. Total PSA, as measured in the blood, is a combination of free (not protein bound) PSA and bound (protein bound) PSA. Patients with prostate cancer have a higher percentage of their PSA bound and a lower percentage of free PSA. Specifically, if the percent free PSA is less than twenty-five percent, the suspicion for prostate cancer rises. If two fifty-year-old men both with normal digital rectal exams have identical PSAs of 5.0, they may not be treated the same. If the first man has a free PSA of sixty percent, he could be re-examined in four to six months with another PSA. If the second man has a free PSA of ten percent, he should be considered for a biopsy.

Prostate Cancer Follow Up
After treatment for prostate cancer, the PSA should drop significantly. Any subsequent rise in the PSA can suggest recurrent cancer. For patients who are treated with a radical prostatectomy, the PSA should drop to zero within two to three months of surgery. Patients treated with radiation therapy should see a PSA titer of less than or equal to 0.5 ng/cc.

Current Recommendations for Patients Obtaining a PSA

• All males over the age of 50 should have a routine yearly PSA.
• African American males and males with a family history of prostate cancer should have a yearly PSA over the age of 40.
• Any male with an exam suspicious PSA for cancer.