Until recently, prostate cancer was one of those topics that wasn’t talked about very much, so a lot of men didn’t know whether they should worry about it. Fortunately, this situation is changing, at least partly because of Movember — a moustache-growing charity event in support of men with prostate cancer.
Once you become aware of prostate cancer, of course, the statistics can be scary. During his lifetime, a man has a 1 in 6 (or 16%) chance of being diagnosed with prostate cancer, and a 1 in 33 (or 3%) chance of dying from it. In 2011, prostate cancer killed 4,100 Canadian men, making it the third most common cause of cancer deaths in men, after lung and colorectal cancer.
Unlike many cancers, however, prostate cancer can be discovered at an early stage through a simple blood test. Prostate-specific antigen, or PSA, is a normal protein found in the prostate gland, and all men have a small amount in their blood. It is measured in nanograms of PSA per millilitre (ng/mL) of blood:
- 0 to 2.5 ng/mL is considered low (normal)
- 2.6 to 10 ng/mL is slightly to moderately elevated
- 10 to 19.9 ng/mL is moderately elevated
- 20 ng/mL or higher is significantly elevated.
When a PSA blood test shows a higher than normal level of this protein, this is an indication that prostate cancer may be present. However, there are many reasons for high PSA levels that have nothing to do with cancer, such as a urinary tract infection, an enlarged prostate, or even just having had sexual intercourse close to the time of a PSA test.
(Here’s a sense of how common high PSA levels are: On average, if 100 men over the age of 50 have a PSA test, 85 of them will have normal PSA levels and 15 will have elevated levels. Of those 15, only three will actually have cancer.)
If a man’s PSA test shows an elevated PSA level, this basically means that more testing may be required. This could mean taking another PSA test, or it could mean other kinds of tests. For example, men with significantly elevated PSA levels often have an ultrasound image taken of their prostate while a small sample of prostate tissue is removed. Examination of the prostate tissue can show whether or not cancer cells are present.
It was recommended in the past that all men over 40 who are at higher risk of developing prostate cancer have a PSA test and a rectal exam every year. (You’re a man at higher than average risk if you’re over 65, are of African heritage, eat a diet high in animal fats, or have a father or brother who had prostate cancer.)
However, today there are differing opinions about whether doing these tests actually reduces the death rate from prostate cancer. This is something you should discuss with your doctor before testing, so that you can make an informed decision about whether you want to be tested. There are good arguments on both sides of the issue.