Prostrate Cancer Tests

Cases of Prostrate cancer have increased over the years and more is being known about the disease. However, diagnostic testing can be less accurate than desired. Since its introduction twenty years ago, the prostrate-specific antigen (PSA) blood test has become a key tool in screening men for prostrate cancer. Until the PSA test, men received only a digital rectal exam or DRE, in which the doctor inserts a gloved, lubricated finger into the rectum to feel the prostrate for lumps and thickenings that suggest a tumor. The PSA test became popular because it can help detect some prostrate cancers earlier than the DRE alone. However, now, after years of use, experts disagree about whether men should receive routine PSA testing and what are normal readings.

What is a normal PSA reading? Until the last several years, it was defined as below 4.0ng/ml, but newer data on prostrate cancer have made it clear that a man’s risk often rises at lower PSA levels. Many experts now say that 2.5 or below is normal for men in their 40’s, up to 3.5 for men in their 50’s, up to 4.5 for those in their 60’s, and 6.5 for men 70 and older. PSA levels naturally rise as the age increases despite any evidence of cancer. In recent years, several variations on the PSA test have been used to improve its accuracy at indicating prostrate cancer and limit the number of men who are advised to receive a biopsy. Most PSA floats through the bloodstream bound to protein molecules, while a smaller portion is “free”. Evidence has shown that when PSA is produced by cancer, higher levels than usual are in the bound form, and a smaller proportion is free.
Less free PSA means a greater chance that it’s cancer. This test is recommended for men who have abnormal results from the standard PSA test.

If your doctor suspects a prostrate infection, he should prescribe a course of antibiotics before repeating the PSA test. If a biopsy is indicated, your doctor will refer you to a surgeon who will perform the procedure. The surgeon will use a needle like device that is guided through a hole in the probe to take tiny tissue samples from the prostrate for examination under a microscope. The surgeon will take at least 12 tissue samples, which decreases the false results. Injecting local anesthesia into nerves at the base of the prostrate makes the procedure less painful. Following the biopsy, there may be slight soreness in the area around the rectum for a few days. Doctors suggest that all men over 50 years old get tested, and those at high risk of getting the disease (African American and a family history of the disease) get tested starting at age 40.