Screening—which basically means testing for a disease in people without symptoms—can help find some types of cancer early, such as prostate cancer, when it’s more easily treated. But for some men, the risks of prostate cancer screening may outweigh the benefits. This is something we emphasize to our male patients at Westchester Health, make sure they understand both the risks and benefits before deciding to undergo screening. To clarify the subject, here is some helpful information.
The 2 main screening tests for prostate cancer:
1. PSA test
Prostate-specific antigen (PSA) is a substance made by cells in the prostate gland (both normal cells and cancerous ones). PSA is mostly found in semen, but a small amount is also found in the blood. The chance of having prostate cancer goes up as the PSA level goes up.
Most men without prostate cancer have PSA levels under 4 nanograms per milliliter (ng/mL) of blood. When prostate cancer develops, the PSA level usually goes above 4. However, 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 physician may advise either waiting a certain amount of time and then repeating the test, or getting a prostate biopsy to find out if you have cancer. When considering whether to do a prostate biopsy to look for cancer, not all physicians use the same PSA cutoff point. Some may advise it if the PSA is 4 or higher, while others might recommend it starting at a lower level, such as 2.5 or 3. Other factors, such as your age, race and family history, may affect this decision.
Factors that might affect PSA levels
A number of factors other than prostate cancer can also raise PSA levels:
- An enlarged prostate: Conditions such as benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate that affects many men as they grow older, can raise PSA levels.
- Older age: PSA levels normally increase slowly as you get older, even if you have no prostate abnormality.
- Prostatitis: This refers to infection or inflammation of the prostate gland, which can raise PSA levels.
- Ejaculation: This can make the PSA increase for a short time, and then decrease again. This is why some physicians suggest that men abstain from ejaculation for a day or two before testing.
- Riding a bicycle: Some studies have suggested that cycling may raise PSA levels (possibly because the seat puts pressure on the prostate), although not all studies have found this.
- Certain urologic procedures: Some procedures that affect the prostate, such as a prostate biopsy or cystoscopy, can result in higher PSA levels for a short time. Some studies have suggested that a digital rectal exam (DRE) might raise PSA levels slightly, although other studies have not found this. Still, if both a PSA test and a DRE are being done during a screening exam, some physicians advise having the blood drawn for the PSA before having the DRE.
- Certain medicines: Taking male hormones like testosterone (or other medications that raise testosterone levels) may cause a rise in PSA.
Some factors that might cause PSA levels to go down (even if a man has prostate cancer):
- 5-alpha reductase inhibitors: Certain drugs used to treat BPH or urinary symptoms may lower PSA levels. These drugs can also affect prostate cancer risk. Tell your physician if you are taking these medicines because they may lower your PSA levels.
- Herbal mixtures: Some dietary supplements may also mask a high PSA level. This is why it’s important to let your doctor know if you are taking any type of supplement, even ones that are not necessarily meant for prostate health.
- Obesity: Extremely overweight men tend to have lower PSA levels.
- Aspirin: Some research has suggested that men taking aspirin regularly may have lower PSA levels. This effect may be greater in non-smokers. If you take aspirin regularly (e.g., to help prevent heart disease), talk to your physician before you stop taking it for any reason.
- Statins: Some studies have linked the long-term use of cholesterol-lowering drugs known as statins with lower PSA levels.
- Thiazide diuretics: Thiazide diuretics are a type of water pill often used to treat high blood pressure. Long-term use is linked to lower PSA levels.
For men not known to have prostate cancer, it’s unclear whether lowering the PSA is helpful.
In some cases, what lowers the PSA may also lower a man’s risk of prostate cancer. But in other cases, it might lower the PSA level without affecting the risk. This could actually be harmful, if it were to lower the PSA from an abnormal level to a normal one, as it might result in not detecting a cancer. This is why, again, it’s important to talk to your physician about anything that might affect your PSA level.
2. Digital rectal exam (DRE)
A digital rectal exam (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.
For a DRE, a physician inserts a gloved, lubricated finger into the rectum to feel for any bumps or hard areas on the prostate that might be cancer. Prostate cancers often begin in the back part of the gland, which might 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 amount of time.
At what age should you have your first screening test?
The American Cancer Society recommends that men at average risk of prostate cancer should be screened starting at age 50. Men at higher than average risk should be screened at age 40 or 45.
Some men are at higher risk than others
African American men and men who have a father, brother or son who were diagnosed with prostate cancer when they were younger than 65 are at high risk. Men with more than one close relative diagnosed before age 65 are at even higher risk.
Should all men be screened for prostate cancer?
It would seem to make sense to check all men to determine if they have prostate cancer. But screening isn’t perfect. Sometimes screening misses cancer, and sometimes it finds something suspicious that turns out to be harmless. Also, there aren’t reliable tests yet to tell the difference between prostate cancer that’s going to grow so slowly it will never cause problems, and dangerous cancer that will grow quickly. Plus, studies have not been able to show that annual PSA screening helps men live longer.
Additionally, treatments for prostate cancer can sometimes have urinary, bowel and sexual side effects that may seriously affect a man’s quality of life. Therefore, screening really is a decision that each individual man should make after having all the information available.
Resources to learn more
Wondering when and if you should get screened for prostate cancer? Come see us.
If you think you should get screened for prostate cancer but want more information, please call (914) 232-1919 to make an appointment with one of our Westchester Health urologists. He/she will perform a thorough examination, get a detailed family history, discuss all your options with you and take all the time as is necessary to answer your questions. Then together, you’ll decide the best course of action. Whenever, wherever you need us, we’re here for you.
By Jerry Weinberg, MD, a Urologist with Westchester Health, member of Westchester Health Physician Partners