Factors affecting the prostate specific antigen (PSA)
There are many factors that affect a man’s PSA, and very often lead to him being needlessly treated for prostate cancer (PC).
If a man’s PSA number is higher than a doctor thinks it should be for his age, the doctor will very often recommend a biopsy. If the biopsy shows positive for PC, the man will invariably be treated, whether he needs to be treated or not. Most men will die with, not from, PC.
The following are factors that affect the PSA, (Very few physicians ask about these factors).
1- PSA Assay (Test). In the USA there are about five (5) different companies that have a PSA Assay. All are good, but usually differ slightly from each other, and may cause a doctor to believe that the PSA has changed. Be consistent, and have a PSA at the same institution, or with the same assay
2- PSA can fluctuate with the time of day, (Circadian Fluctuation) by as much as thirty seven percent (37%). Either go between about 8 to 10 am, 10 am to noon, 1 to 3 pm or 3 to 5pm. This will minimize any fluctuation. The narrower the time range, the better.
3 Do not have a PSA taken within a few days after a Digital Rectal Exam (DRE), or within 1 month of a colonoscopy, cystoscopy, Foley insertion (catheter in the penis), as the PSA will show a small, but false elevated reading
4- Prostatitis, an infection or inflammation in the prostate will show a false elevated PSA that has nothing to do with PC. An antibiotic taken for about a week will usually resolve this situation.
5-Riding a bicycle, motorcycle, or a riding lawn mower, a day or two before a PSA, will show a small, but false elevated PSA.
6- Having an ejaculation, up to three (3) days before a PSA, will show an elevated reading of up to 41%.
7- An enlarged prostate will normally generate more PSA, because prostate cells do this. An enlarged prostate is not PC. This is a constant, and does not fluctuate.
Add two more of the above to any small changes in your PSA, and algebraically the man’s PSA will show a huge elevation to your PSA, without there being any change in a person’s medical condition
Men who are doing Watchful Waiting /Active Surveillance will very often have slight rises in their PSAs, without requiring any treatment. This is true even with PSAs in the teens or higher, as long as the change is gradual. Let the Medical Oncologist guide you
5-3-2012 Ref 3/24/10