Prostate cancer screening: Should you get a PSA test?

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Prostate cancer screening: Should you get a PSA test?
Making the decision to have a PSA test depends on a variety of factors. Here are some tips that will help you make a good decision.

Cancer screening tests — including PSA tests to look for signs of prostate cancer — can be a good idea. They can help identify cancer early on, when treatment is most effective. A normal PSA test, combined with a digital rectal exam, can help reassure you that it's unlikely you have prostate cancer. But, getting a PSA test for prostate cancer may not be necessary for some men, especially men 75 and older.

Professional organizations vary in their recommendations about who should — and who shouldn't — get a PSA screening test. While some have definitive guidelines, others leave the decision up to men and their doctors. The organizations that do make recommendations generally encourage PSA testing in men between the ages of 50 and 75, and in men with an increased risk of prostate cancer. Ultimately, whether you should have a PSA test is something you'll have to decide after discussing it with your doctor, considering your risk factors and weighing your personal preferences.

What is a PSA test?
Prostate-specific antigen (PSA) is a protein produced by both cancerous (malignant) and noncancerous (benign) prostate tissue. PSA helps liquefy the semen. A small amount enters the bloodstream. Cancer cells usually make more PSA than do benign cells, causing PSA levels in your blood to rise. However, determining what a high PSA score means can be complicated. Besides the PSA number itself, your doctor will consider a number of other factors to evaluate your PSA scores:

Your age
The size of your prostate gland
How quickly your PSA levels are changing
Whether you're taking medications that affect PSA measurements, such as finasteride (Propecia, Proscar), dutasteride (Avodart) and even some herbal supplements
When elevated PSA isn't cancer
While high PSA levels can be a sign of prostate cancer, a number of conditions other than prostate cancer also can cause PSA levels to rise. These other conditions could cause what's known as a "false-positive" — meaning a result that falsely indicates you might have prostate cancer when you don't. Conditions that could lead to an elevated PSA level in men who don't have prostate cancer include:

Benign prostate enlargement (benign prostatic hyperplasia)
A prostate infection (prostatitis)
Other less common conditions
False-positives are common. Only about one in four men who have a positive PSA test turns out to have prostate cancer.

When prostate cancer doesn't increase PSA
Some prostate cancers, particularly those that grow quickly, may not produce much PSA. In this case, you might have what's known as a "false-negative" — a test result that incorrectly indicates you don't have prostate cancer when you do.

Because of the complexity of these relating factors, it's important that a physician experienced in interpreting PSA levels evaluates your situation. You want to avoid unnecessary follow-up testing and treatment, but you want to be aware of false-negatives, so don't ignore warning signs.

What's the advantage of a PSA test?
Detecting certain types of prostate cancer early can be critical. Elevated PSA results may reveal prostate cancer that's likely to spread to other parts of your body (metastasize), or they may reveal a quick-growing cancer that's likely to cause other problems. Early treatment can help catch the cancer before it becomes life-threatening or causes serious symptoms. In some cases, identifying cancer early means you will need less aggressive treatment, reducing your risk of side effects such as erectile dysfunction and incontinence. If you are in a group of men at high risk of prostate cancer, you're even more likely to benefit from PSA tests.

What's risky about a PSA test?
You may wonder how getting a test for prostate cancer could have a downside. After all, there's little risk involved in the test itself — it requires simply drawing blood for evaluation in a lab. However, there are some potential dangers once the results are in. These include:

Worry about false-positive results caused by elevated PSA levels from something other than prostate cancer.
Invasive, stressful, expensive or time-consuming follow-up tests.
False reassurance from a PSA test that doesn't reveal cancer (false-negative), leading to a missed diagnosis of aggressive prostate cancer that needs treatment.
Stress or anxiety caused by knowing you have a slow-growing prostate cancer that doesn't need treatment.
Deciding to have surgery, radiation or other treatments that cause side effects that are more harmful than untreated cancer.
Digital rectal examination


PSA tests aren't the only screening tool for prostate cancer. Digital rectal examination (DRE) is another important way to evaluate the prostate and look for signs of cancer. Your doctor performs the test by inserting a gloved, lubricated finger into your rectum to feel the prostate for bumps or other abnormalities. It's a quick, safe and easy test for your doctor to do. In addition to checking for signs of prostate cancer, a digital rectal exam may also reveal signs of rectal cancer. A DRE should always be done with a PSA test when screening for prostate cancer. This will help minimize the risk of missing prostate cancer — or wrongly identifying a benign prostate abnormality as cancer.

Simple test, not-so-simple decision
Because there are no clear answers on who should have PSA screening, consider the pros and cons of the test.

Pros of PSA screening Cons of PSA screening
PSA screening may help you detect prostate cancer early. Many prostate cancers are slow growing and never spread beyond the prostate gland.
PSA testing can be done with a simple, widely available blood test.
PSA tests can't tell the difference between prostate cancer and other noncancerous prostate conditions, such as infection (prostatitis) or benign prostate enlargement (BPH). Thinking you have cancer when you don't can cause stress and worry — as well as unnecessary and potentially risky follow-up tests.

On the other hand, PSA tests don't always reveal prostate cancer when it's present. In some cases, false reassurance from normal PSA results (a false-negative) can actually delay a diagnosis of prostate cancer that needs treatment.

For some men, knowing is better than not knowing. Having the test can provide you with a certain amount of reassurance — either that you probably don't have prostate cancer or that you do have it and can now have it treated. You may end up with a diagnosis of prostate cancer that is not a threat to your health and doesn't require treatment. This can cause anxiety and unnecessary testing with risks of pain, bleeding and infection.
Cancer is easier to treat and is more likely to be cured if it's diagnosed in the early stages of the disease. Not all prostate cancers need treatment. Treatment for prostate cancer can have serious risks and side effects, including urinary incontinence, erectile dysfunction or bowel dysfunction.
The number of deaths from prostate cancer has gone down since PSA testing became available. There is no clear evidence that the decrease in deaths from prostate cancer is due to early detection and treatment based on PSA or due to other factors. In fact, in numerous studies, men who get screened have not been shown to live longer than men who don't.
Think about your risk factors for prostate cancer
Knowing the risk factors for prostate cancer can help you determine if and when you want to begin prostate cancer screening. The main risk factors include:

Age. As you get older, your risk of prostate cancer increases. After age 50, your chance of having prostate cancer increases substantially. The majority of prostate cancers are found in men age 65 years or older. The option to have PSA testing begins at age 50 (40 if you have risk factors) and continues until you're at the age when your life expectancy is 10 years or fewer. Once you reach that age, the likelihood that a prostate cancer would progress and cause problems during the remainder of your lifetime is small. In fact, the U.S. Preventive Services Task Force does not recommend prostate cancer screening in men 75 and older.
Ethnic background. For reasons that aren't well understood, black men have a higher risk of developing and dying of prostate cancer.
Family history. If a close family member — your father or brother — has prostate cancer, your risk of the disease is greater than that of the average American man.
Diet. A high-fat diet and obesity may increase your risk of prostate cancer.
Consider the varying viewpoints: What are the recommendations?
Organization Recommendation
American Urological Association (AUA) The AUA encourages men who are in good health to have annual PSA testing starting at age 50, or at age 40 if they're in high-risk groups, such as black men or those with a father, brother or son with the disease.
American Cancer Society (ACS) The ACS recommends that doctors offer the test to men age 50 and older who expect to live another 10 years, and test men at high risk if they're age 45 and older.
Centers for Disease Control and Prevention (CDC) The CDC considers the evidence insufficient to determine whether the benefits outweigh the harms.
U.S. Preventive Services Task Force (USPSTF) The USPSTF does not recommend prostate cancer screening in men 75 and older, or in men who will probably live 10 years or fewer. For men under 75, the USPSTF considers the evidence insufficient to determine whether the benefits outweigh the harms.
American College of Preventive Medicine (ACPM) The ACPM recommends that a man decide about whether to have PSA testing after discussing the risks and benefits with his doctor. The ACPM considers the need for screening questionable in elderly men with other chronic illnesses and men with life expectancies of less than 10 years.
How does it add up?
A positive PSA test can be a lifesaver for some men, identifying prostate cancer that needs treatment early. It's generally a good idea to have PSA testing done if you're at increased risk of prostate cancer. However, not all men need to have the screening. You may want to think twice if you're in a group of men unlikely to benefit from it. After considering the pros and cons of screening, your age, general health and risk factors, your preferences and what the experts say, talk to your doctor. Together you can make the right decision for you.