There are two primary methods used to initially detect abnormalities in the prostate that may be cancerous.
Prostate-Specific Antigen (PSA)
The first is the prostate-specific antigen (PSA) blood test. Prostate cancer can often be found early by testing the amount of prostate-specific antigen in your blood. PSA levels can be high not only in men who have prostate cancer, but also in men with an enlarged prostate gland or infections of the prostate. PSA tests may be very useful for early cancer diagnosis. However, PSA tests alone do not always reveal whether cancer is present.
Digital Rectal Examination (DRE)
Prostate cancer may also be found when your doctor does a digital rectal examination (DRE). Because your prostate gland lies just in front of your rectum, the doctor can feel if there are any nodules or areas of abnormal hardness in your prostate. These indicate the need for further testing to see if there is a cancer.
Benefits of Yearly Examinations
If you have yearly examinations and either one of these test results becomes abnormal, any cancer that you may have has probably been found at an early, more treatable stage.
Since about 1990, when the use of early detection tests for prostate cancer became relatively common, the prostate cancer death rate has dropped. But it has not been proven that this is a direct result of screening. Studies are underway to try to prove that early detection tests for prostate cancer in large groups of men will lower the prostate cancer death rate. Until that information is available, whether you have the test is something for you to decide in consultation with your doctor. Factors to consider are your age and general health. If you are young and develop prostate cancer, it will probably shorten your life if it is not caught early. If you are older or in poor health, then prostate cancer may never become a major problem because it is generally a slow-growing cancer.
Neither of the available screening tests for prostate cancer is infallible. Screening tests check for disease in a person who shows no symptoms. Most men with mildly elevated PSA do not have prostate cancer, and many men with prostate cancer have normal levels of PSA. Also, the digital rectal exam can miss many prostate cancers.