Prostate cancer for a man, like breast cancer for a woman, is one of the most threatening types of cancer to self-esteem and psychological well-being. While it is well-known that prostate cancer has a good prognosis and that it is rarely fatal when treated soon enough, it is the cause of many fears for a man including impotence and incontinence. As the awareness of the importance of screening for various cancers has grown, men are under increasing pressure from the significant others in their lives and from their doctors to have a PSA examination, and they often need to learn more about it.
What is the prostate-specific antigen (PSA) test?
A PSA exam is a blood test to determine the levels of prostate specific antigens (PSA) in the blood. Your doctorwill draw a sample of your blood, which is then sent to a lab for testing. The results are the level of PSA you have in your body, which is then compared to the expected amount. For most men, low levels of PSA are the norm. Under certain conditions the level will be higher, including cancer, but also inflammation and enlargement of the prostate. As men get older both possibilities are more likely, so the doctor will want to also give you a digital rectal exam (DRE) to know for certain what the raised level means.
Why is the PSA test performed?
The PSA exam has been recommended by the FDA for over 50 years as an essential part of the typical physical examination for men over the age of 50. At this stage it is a screening test, meaning that it is used to see if there is disease present. The test is also used for men who have undergone treatment for prostate cancer to see if the cancer is growing or shrinking. Doctors have differing points of view on how often the PSA exam should be done after a man reaches the 50-year mark. Some will do it every year, some will recommend it every 5 years. Because there are other factors involved (age and family history), some doctors will increase the frequency of the tests as a man gets older.
How are PSA test results reported?
The results of a PSA blood test are reported as nanograms of PSA per milliliter of blood. With many tests of blood levels – cholesterol, hormones, etc. – it is fairly simple for a doctor and the patient to compare the results to a standard amount and proceed with some confidence. With PSA levels, the situation is more complex. There is no normal or standard level, and PSA levels are not related to the probability of cancer on a one-to-one basis – some men have higher levels but no cancer (known after a biopsy), and some have lower levels but have cancer. Also, the level of PSA in the blood is known to increase with age even though no cancer is present.
For these reasons the usefulness of the PSA exam has been questioned, but it is still considered a necessary part of a physical for men over 50. If there is any sign of an elevated level, the doctor can consider the results along with the DRE and decide on a course of action. Other tests can be done and if cancer is suspected a biopsy will give a definitive answer. Because the results of the PSA exam can be ambiguous and not final, it is important for every man to work with his doctor to understand how to best proceed. The exam is merely the starting point for a healthy prostate.