At this website, if you guessed “public service announcement” – you would be incorrect. However, our post is a public service announcement of sorts. For the purposes of our post, PSA is the acronym for Prostate-Specific Antigen.
So, what is a prostate-specific antigen? This is an excellent question. Prostate-specific antigen (PSA) is a substance that is produced by the prostate gland. The PSA levels are identified via a PSA blood test.
Elevated levels of prostate-specific antigen are an indicator to the potential existence of prostate cancer. However, that is not all it may indicate. It may indicate an enlarged prostate gland or prostatitis. Prostatitis is a disease of the prostate gland often accompanied by groin pain, painful urination, and difficulty urinating among other symptoms.
The majority of men have a PSA level of under four nanograms per milliliter (4 ng/ml). This figure is the baseline or “cut-off” as the red flag indicating the potential existence of prostate cancer. While prostate cancer may exist at any PSA level, those with a PSA level higher than 4 ng/ml are often the most likely to have it.
Recent studies done by the Duke University Cancer Center have demonstrated for scientists how PSA levels may reflect prostate cancer progression. Additional studies have indicated the following probabilities for prostate cancer in men who have had normal prostate gland results from a digital prostate exam and the following PSA levels (source – WebMD):
- PSA less than 4 ng/ml have a 15% chance of having prostate cancer
- PSA between 4 ng/ml and 10 ng/ml have a 25% chance of having prostate cancer
- PSA higher than 10 ng/ml have a 67% chance of having prostate cancer
Historically, the less-than 4 ng/ml PSA level has been used by most health officials as being normal. More recently, it is clear that this is a moving target depending upon certain circumstances, with some researchers suggesting using 2.5 – 3.0 ng/ml as the upper limit for the classification of PSA levels as normal. This is especially true for younger patients as their smaller prostates will produce lower normal value PSA levels. Therefore, prostate-specific antigen levels that are higher than 2.5 ng/ml but less than 4.0 ng/ml may still be cause for alarm.
Additionally, it is equally important to analyze trend data over time. How the PSA level rises and/or falls over periods of time should also be considered when making an assessment for one’s prostate cancer risk.
The bottom line is that up until such time as the prostate cancer concerns require a biopsy for a confirmed determination of the presence of prostate cancer, no single test is considered perfect. The digital prostate exam, the PSA blood test, and all subsequent tests, utilized in conjunction with one another give physicians the best information to draw such a conclusion. The reality is that many men with elevated prostate-specific antigen levels have noncancerous prostate enlargement. This prostate enlargement comes over the normal course of aging. While most cases of prostate cancer can be identified as present by the PSA blood test, keep in mind that low PSA levels are not a guarantee of being cancer free.