Prostate Cancer
with Thomas Smyth, MD
How do you interpret the score of PSA?
When it comes to diagnosing prostate cancer, an annual physical is of utmost importance. In addition to testing your blood and urine, there are two other crucial exams: a DRE (digital rectal exam) and a PSA (prostate-specific antigen).
In a DRE, your doctor inserts a lubricated, gloved finger to check your prostate. He or she is feeling for abnormalities, including an enlarging or hardness of the prostate. However, “This test is far from perfect”, says Dr. Thomas Smyth, MD at GBMC.
Dr. Smyth explains, “This is a subjective test. We can only feel part of the prostate. 30% of prostate cancers grow in areas that can’t be reached. Also, two different doctors might feel two different things. What one considers hardening, the other may not.”
This is why a PSA in conjunction with a DRE is so important. Originally used to evaluate the specific stage of prostate cancer in diagnosed patients, the PSA quickly became a diagnostic tool. A PSA measures the amount of prostate-specific antigen in your blood. This antigen is released into the blood by the prostate gland. The lower the amount of PSA, the healthier the prostate. Dr. Smyth says, “A score of 2.5 or below is normal for someone under 50. If you’re under 60, it’s 3.5 or below. A score of 4.5 is normal for someone under 70. If you’re over 70, 6.5 is considered normal.”
Some doctors use 2.5 or below for all patients. But the problem according to Dr. Smyth “Many men were getting a biopsy who didn’t need one. The goal is to diagnose those with clinically significant prostate cancer without diagnosing those with clinically insignificant cancers.”
Dr. Smyth says there are also other good indicators. One entails determining your PSA density, in other words, dividing the size of your prostate by your total PSA. Another measures your percentage of free PSA. If your total PSA is between four and ten, and your percentage-free PSA is greater than 26, you are in a safer range.
Other tests include a transrectal ultrasound (TRUS). In a TRUS, sound wave echoes are used to create an image of the prostate gland to check for abnormalities. Your doctor might also use a TRUS for guidance in needle biopsies or guiding nitrogen probes in cryosurgery.
Dr. Smyth notes that prevalence in much higher for African-American men and those with a family history. Both of these groups should start testing at 40. Also, prostate cancer seems to be more prevalent in countries at higher latitudes. This could suggest an association between lower amounts of Vitamin D, sunlight and prostate cancer.
More men are cognizant of prostate cancer now than 20 years ago, according to Dr. Smyth. He also says, “In 1992, there were approximately 40,000 deaths attributed to prostate cancer according to the American Cancer Society. The latest data, which is from 2002, shows a drop to 29,000. This is due to a combination of improvements in early diagnosis techniques and an improvement in the treatment of those in the early stages of prostate cancer.”
While men are often afraid of getting tested, Dr. Smyth says, “It’s better to know you have the disease, and that you have options to treat it, than to be unaware you have it. The longer you wait to get tested, the more you significantly narrow your options if you have prostate cancer. With early diagnosis, you will have many treatment options at your disposal and minimal impact to your quality of life. ”
