Prostate cancer screening: Should you get a PSA test?

Cancer screening tests — including the prostate-specific antigen (PSA) test to look for signs of prostate cancer — can be a good idea. Prostate cancer screening can help identify cancer early on, when treatment is most effective. And 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. Organizations that do recommend PSA screening generally encourage the test in men between the ages of 40 and 75, and in men with an increased risk of prostate cancer.  Ultimately, whether you have a PSA test is something you should decide after discussing it with your doctor, considering your risk factors and weighing your personal preferences.

Here's more information to help you prepare for a conversation with your doctor about PSA testing.

Normal prostate gland

Normal prostate gland

The prostate gland is located just below a man's bladder and surrounds the top portion of the urethra, the tube that drains urine from the bladder. The primary function of the prostate is to produce ...

Simple test, not-so-simple decision

There are a number of pros and cons to the PSA test.

What is PSA?

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 of PSA normally enters the bloodstream. Cancer cells usually make more PSA than do benign cells, causing PSA levels in your blood to rise. But PSA levels can also be elevated in men with enlarged or inflamed prostate glands. Therefore, 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 1 in 4 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 doctor experienced in interpreting PSA levels evaluates your situation.

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 testing.

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.

Digital rectal exam

Digital rectal exam

During a digital rectal exam, your doctor inserts a gloved, lubricated finger into your rectum and feels the back wall of the prostate gland for enlargement, tenderness, lumps or hard spots. ...

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 40 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.
• 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 — was diagnosed with prostate cancer before age 65, your risk of the disease is greater than that of the average American man. If several of your first-degree relatives — father, brothers, sons — have had prostate cancer at an early age, your risk is considered very high.
• Diet. A high-fat diet and obesity may increase your risk of prostate cancer.

Consider the varying viewpoints: What are the recommendations?

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.

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