- Age 50 for men who are at average risk of prostate cancer and are expected to live at least 10 more years.
- Age 45 for men at high risk of developing prostate cancer. This includes African Americans and men who have a first-degree relative (father, brother, or son) diagnosed with prostate cancer at an early age (younger than age 65).
- Age 40 for men at even higher risk (those with more than one first-degree relative who had prostate cancer at an early age).
After this discussion, those men who want to be screened should be tested with the prostate-specific antigen (PSA) blood test. The digital rectal exam (DRE) may also be done as a part of screening.
Because prostate cancer often grows slowly, men without symptoms of prostate cancer who do not have a 10-year life expectancy should not be offered testing since they are not likely to benefit. Overall health status, and not age alone, is important when making decisions about screening.
Even after a decision about testing has been made, the discussion about the pros and cons of testing should be repeated as new information about the benefits and risks of testing becomes available. Further discussions are also needed to take into account changes in the patient's health, values, and preferences.
Prostate cancer is the second most common cancer among men, after skin cancer. More than 2 million men in the US count themselves as prostate cancer survivors.
To understand prostate cancer, it helps to know about the prostate and nearby structures in the body. The prostate is a gland found only in males. It is located below the urinary bladder and in front of the rectum. The size of the prostate changes with age. In younger men, it is about the size of a walnut, but it can be much larger in older men.
Several types of cells are found in the prostate, but almost all prostate cancers develop from the gland cells, which are the cells that make the prostate fluid that is added to the semen. The medical term for a cancer that starts in gland cells is adenocarcinoma.
Other types of cancer can also start in the prostate gland, including sarcomas, small cell carcinomas, and transitional cell carcinomas. But these other types of prostate cancer are so rare that if you have prostate cancer it is almost certain to be an adenocarcinoma.
Prostate-specific antigen (PSA) blood test
Prostate-specific antigen (PSA) is a substance made by cells in the prostate gland (both normal cells and cancer cells). PSA is mostly found in semen, but a small amount is also found in the blood. Most healthy men have levels under 4 nanograms per milliliter (ng/mL) of blood. The chance of having prostate cancer goes up as the PSA level goes up.
When prostate cancer develops, the PSA level usually goes above 4. Still, a level below 4 does not guarantee that a man doesn’t have cancer – about 15% of men with a PSA below 4 will have prostate cancer on a biopsy. Men with a PSA level between 4 and 10 have about a 1 in 4 chance of having prostate cancer. If the PSA is more than 10, the chance of having prostate cancer is over 50%.
If your PSA level is high, your doctor may advise either waiting a while and repeating the test, or getting a prostate biopsy to find out if you have cancer. Not all doctors use the same PSA cutoff point when advising whether to do a biopsy. Some may advise it if the PSA is 4 or higher, while others might recommend it at 2.5 or higher. Other factors, such as your age, race, and family history, may also come into play.
DRE Digital rectal exam
For a digital rectal exam (DRE), the doctor inserts a gloved, lubricated finger into the rectum to feel for any bumps or hard areas on the prostate that might be cancer. As shown in the picture below, the prostate gland is just in front of the rectum, and most cancers begin in the back part of the gland, which can be felt during a rectal exam. This exam can be uncomfortable (especially for men who have hemorrhoids), but it usually isn’t painful and only takes a short time.
DRE is less effective than the PSA blood test in finding prostate cancer, but it can sometimes find cancers in men with normal PSA levels. For this reason, it may be included as a part of prostate cancer screening.