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Many doctors recommend that every man over 40 get a blood test called Prostate Specific Antigen to check for prostate cancer. However, PSA levels can be raised abnormally high by:
• prostate infections,
• a benign enlarged prostate,
• riding a bicycle,
• making love, or
• having a doctor check the prostate.
Prostate Specific Antigen is made by prostate cells and is released into the bloodstream. Large prostates have more PSA, so a rise in PSA means that the gland is enlarging rapidly, which can be a sign of cancer or that the prostate is irritated by rubbing or infection. Any manipulation of the prostate raises blood PSA levels (1). PSA levels can be raised for several hours just by having your prostate checked by a physician (2,3), so PSA blood tests should be drawn before the doctor examines the prostate (4). Having a climax raises PSA for up to 48 hours (5,6,7,8,9,10,11,12). Infections raise PSA and there is no way to tell the difference between a PSA raised by cancer or by infection (13).
PSA can be classified into two different fractions called free and bound PSA. Free PSA is made by a normal prostate, while bound PSA is made primarily by prostate cancer cells. The usual rule is that if a man’s PSA is above 4 (normal 0-4), the free PSA should be at least 18 percent of the total PSA. This rule usually holds for every situation except infection. The ratio of free PSA to bound PSA is the same for prostate cancer and infections (14).
If you have an elevated PSA blood test, your doctor will check your prostate and order a sonogram to see if you have a nodule that may be a sign of cancer. Most urologists recommend a biopsy done in their offices. If your PSA is low, you may have difficulty ejaculating and fathering a child. A normal ejaculate clots and traps sperm. PSA liquifies the clot and allows the sperm to swim toward the egg (16). PSA also causes the muscles of ejaculation to contract(17).
Patients who have been diagnosed with prostate cancer or who are considering whether to be screened for prostate cancer should be told that most older men who have prostate cancer do not have their lives prolonged by treatment. Men under 65 who are treated for prostate cancer may have their lives prolonged when compared to those who were not treated.