Prostate cancer is the abnormal growth of cells in the tissues of the prostate gland . It is the most common cancer in men. Most men who get it are older than 65.

Unlike many other cancers, it is usually slow-growing. For most men, this slow growth means they have time to learn all they can before deciding whether to have treatment or which treatment to have.

Early prostate cancer usually doesn't cause symptoms. When prostate cancer is found early, before it has spread outside the prostate gland, it may be cured with radiation or surgery to remove the prostate. As prostate cancer grows or spreads, symptoms may develop, including urinary problems (such as blood in the urine) and bone pain.

The prostate-specific antigen (PSA) test is a blood test. PSA is released into a man's blood by the cells of his prostate gland. Low amounts of PSA may be found in the blood of healthy men. The amount of PSA in the blood normally increases as a man's prostate enlarges with age. And it increases after ejaculation and after trauma to the prostate caused by such things as a long bike ride. It is also increased by inflammation of the prostate gland (prostatitis) and by prostate cancer.

The PSA test is usually done along with a digital rectal exam. Together they can help identify men who may have prostate cancer and should consider further tests.

A high PSA result can be the first warning sign of prostate cancer. A high PSA can signal a higher risk of getting prostate cancer in the future. But a high PSA can also be linked to other causes that aren't cancer.

The amount of PSA in the blood normally increases as a man's prostate enlarges with age. But when you have prostate cancer, your PSA level increases even more over time.

The PSA test and digital rectal exam can suggest a problem when there is not one. This is called a false-positive result. Only about 20 to 30 out of 100 men who have a PSA test result greater than 4.0 ng/mL actually have prostate cancer, while 70 to 80 of them don't have prostate cancer.

These tests may also fail to detect a problem when there is one. This is called a false-negative result.

A PSA test alone can't tell if you have prostate cancer. This test only shows the level of your PSA. And a PSA test can't tell why your level is high.

The prostate naturally gets bigger as a man gets older. More than half of all men who are older than 50 have an enlarged prostate. This affects the PSA level, making it less accurate as a way to detect cancer.

Because several other things can make a PSA level go up—for example, ejaculation or an infection in the prostate—your doctor may advise you to have another PSA test later before you make any further decisions.

If your PSA test suggests that you may have prostate cancer, your doctor may recommend a biopsy, which is the only way to make sure that you have prostate cancer. If the biopsy finds cancer, you must decide how or whether to treat it.

A few prostate cancers grow fast. Men who have fast-growing cancers are more likely to die from prostate cancer than men who have slower-growing cancers. But doctors can't tell which kinds of prostate cancer will grow quickly. So this means it's hard to know when treatment is needed. Treatments can have serious long-term side effects. They may cause health problems, including problems with your bladder, bowel, and erections. For this reason, some men choose not to have the PSA test.

In men who have not been diagnosed with prostate cancer, PSA velocity can show that there is a problem that needs further testing. PSA velocity is measured by looking at the rate of change in PSA levels over 2 or 3 years. PSA levels rise faster in men who have prostate cancer than they do in men who have enlarged prostates.

Your chance of getting prostate cancer increases as you age. Men who are younger than 75 and who do not have serious health problems may gain the most from early detection and treatment.

Most medical experts say that men age 50 or older should talk to their doctors about the pros and cons of PSA testing so that they can make their own decisions.

Some experts worry that PSA testing for prostate cancer begins a process that can force a man to make hard decisions and can lead to other health problems that are caused by the treatment for prostate cancer. Here's what some experts say:

• The U.S. Preventive Services Task Force (USPSTF) says that most men should not be given PSA tests as part of routine medical checkups. Instead, each man should talk to his doctor to see if he should have the test.
  • The USPSTF says that men who are 75 or older should not be tested and that younger men should discuss the pros and cons of PSA testing before being tested.
  • The USPSTF also says that men younger than 75 with long-term medical problems and who expect to live less than 10 years are unlikely to benefit from testing.
• The American Cancer Society (ACS) advises men to talk with their doctors about testing and treatment before deciding about testing. The ACS says that men should not be tested without learning about the risks and benefits. The ACS advises talking to a doctor about testing:
  • At age 50 for men who are at average risk of getting prostate cancer and are expected to live at least 10 more years.
  • At age 45 for men at high risk, such as African Americans and men who have a first-degree relative (father, brother, or son) who had prostate cancer when he was younger than 65.
  • At age 40 for men at an even higher risk, such as those with several first-degree relatives who had prostate cancer at an early age.
• The American Urological Association (AUA) recommends that men decide with their doctors about screening. If a man decides to be screened, the AUA says he should start at the age of 40 for a "baseline" score (a baseline score is a PSA level that can be used to compare with future test scores).

Your doctor may recommend a PSA test if he or she thinks you may have prostate cancer.

Your doctor may discuss PSA screening if:

• You are in your 50s or 60s and are in good health.
• Your doctor wants to keep track of changes in your PSA level.
• You are an African American or a Jamaican of African descent, which means that you have a greater chance of getting the kind of prostate cancer that grows and spreads.
• Your father, brother, or son got prostate cancer before age 65.