Prostate Cancer Screening
Who should be screened for prostate cancer, and how often?
The American Cancer Society and the American Urological Association recommend that a yearly screening should be offered to all men over 50 who have a life expectancy of at least 10 years. For African American men, or men with an affected first-degree family member, yearly screening is recommended beginning at age 45. For men who have multiple first-degree relatives affected with prostate cancer at an early age, a baseline screen is advocated at age 40. There are many experts who believe all men should initiate screening at age 40.
Prostate cancer screening methods
Two procedures are commonly used to screen for prostate cancer:
- Digital rectal exam
- Prostate-specific antigen (PSA) test
In the digital rectal exam (DRE), a gloved finger is placed into the rectum to detect bumps or abnormalities on the prostate. About 10–15% of prostate cancers are detected in this manner in men with a normal PSA. It is not as sensitive as the PSA measurement, and depends to some extent on the examiner.
In the PSA test, the amount of PSA in the blood is analyzed. PSA is a substance made only in the prostate. Because it is made by both normal and cancerous cells, an elevated PSA does not necessarily indicate prostate cancer, since it may result from benign enlargement of the prostate (BPH).
Interpreting PSA results
An elevated PSA may result from either benign enlargement of the prostate (BPH) or prostate cancer.
Some general guidelines follow:
There is not a “normal” PSA that excludes prostate cancer or an “abnormal” PSA that is diagnostic of prostate cancer.
- 15% of men with a PSA <4.0 will have prostate cancer.
- 25% of men with a PSA between 2.5 and 4.0 will have prostate cancer.
- 10% of men over 50 will have a reading above 4.0. Roughly 30–40% of these men will have prostate cancer.
- 25% of men of all ages who have a PSA between 4.0 and 10 will have prostate cancer. Cancers in this range have been shown to be clinically important and potentially curable.
- 50% of men with a PSA over 10 will have prostate cancer.
In addition to assessing the PSA value at a given time, your doctor will also take into consideration the rate at which your PSA is increasing each year, if you have had annual PSA tests.
When is further evaluation needed?
Further evaluation, in the form of a biopsy, is recommended for:
- Men under age 60 with a PSA greater than 2.5
- Men over age 60 with a PSA greater than 4.0
- Any man with PSA rising more than 25% per year or 0.75 ng/ml per year