To PSA or Not to PSA. Is that the Question?

29000 Men Comment
Below is a good description of some of the history of PSA testing and accepted PSA values for specific age ranges. The problem with guidelines is that there are the general rule and don’t cover the statistical outliers. For example, I am an accidental prostate cancer survivor. I was diagnosed at age 57 with a PSA value of 3.2, well within the acceptable range according to the standard. I also had a negative DRE, which was misleading because my tumors were sitting on top of the prostate where they could not be felt. My post treatment diagnosis was Stage 2, with a Gleason Score of 3+3. I am only here writing this blog because my urologist was super diligent and ordered a Free PSA test that came back with a very low ratio (.09; 9%).

Prostate cancer kills almost 29,000 men each year. It is up to each man individually to monitor his PSA, track the changes, and then get the facts. I am not suggesting a rush to treatment, but I do believe it is vitally important for men to know if they have prostate cancer as soon as possible. If you are unlucky and are one of the 1 in 6 men that is diagnosed, the next step is to work with the doctor to determine if you have an aggressive form of the disease.

Please visit us at 29000Men.org and participate in one of our prostate cancer awareness events.

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The PSA Test

Understanding the PSA Test and Results

Prostate Specific Antigen (PSA) is a protein made in the prostate. Normally, very little should be found in the blood. Rising levels of PSA in the blood indicate a problem with the prostate, which could be cancer but could also be an enlarged prostate (BPH).

Annual screening should start at age 45 for the general population, but the right age to start PSA testing depends on your level of risk.

Doctors usually recommend further testing for men with a total PSA level of 2.5 or more nanograms of PSA per milliliter of blood (ng/ml). This cut-off level has been set by the National Comprehensive Cancer Network, a large network of cancer experts who establish industry wide standards.

As PSA levels increase, so do the odds that it’s due to prostate cancer. About 25 percent of men with a PSA level from 4 to 10 have prostate cancer. About 67 percent of men with a PSA above 10 have the disease.

The change in your PSA level over time, PSA velocity, is very important. Even if your PSA is 4.0 ng/ml or below, an increase of 50 percent or more in one year may indicate prostate cancer. If your PSA is above 4.0 ng/ml, an increase of 75 percent or more in one year could indicate an aggressive case of the disease.

There are some factors that you and your doctor may want to consider when it comes to interpreting your score:

* Your age. Doctors may use age-adjusted PSA ranges to account for the natural increase in PSA with age when considering further testing.
* The size of your prostate. PSA Density is a measure that relates your PSA level to the size of your prostate, to account for the increase in PSA caused by prostate enlargement.
* Your weight. Body Mass Index, a measure of obesity, may also be a factor. The relationship between obesity and lower PSA levels may cause doctors to miss early prostate cancer cases in overweight men.
* Ejaculation within 48 hours before taking a PSA test can also cause a higher reading of your PSA level.

Some doctors recommend the following PSA cut-off levels adjusted by age and ethnicity:

Age Caucasian or Hispanic African American Asian

40 to 49 2.5 2.0 2.0

50 to 59 3.5 4.0 3.0

60 to 69 4.5 4.5 4.0

70 to 79 6.5 5.5 5.0

PSA Test Standards

Today, because there are two standards for PSA tests, the same cutoff should not be used across all PSA tests. It is important for you and your physician to know which type of test your clinic’s lab uses and how to correctly interpret the results.

The Hybritech PSA test established 4.0 ng/mL as the cutoff for a normal test. This means men with a score above 4.0 should be referred for further testing, such as a biopsy. Men with a result lower than 4.0 may not be referred for biopsy, depending on their physician’s instructions. As other manufactures developed PSA tests, they aligned their tests to the same standard, which became known as the "Hybritech standard," and other manufacturers used the same recommended cutoff of 4.0.

By the mid-1990s, some researchers began to recognize that test results from different test manufacturers could be slightly different and joined together to create a common calibration standard to better align results from different PSA tests. This standard was accepted by the World Health Organization (WHO) and soon became known in the medical community as the “WHO standard” PSA test. To establish this new standard, a different scientific process to measure molecular weight of PSA was used and found that weight to be 20 percent higher than was used for the Hybritech test. Because of the way this is calculated, a WHO test would show a proportionately lower PSA concentration level than would a Hybritech test for the same sample. As a result, the cutoff point at which men are referred for further testing would more appropriately be set about 20 percent lower than the 4.0 used for the Hybritech test.

To find out which type of test you have received, your physician should contact his or her lab to determine which brand of test was used for their PSA testing and whether it is WHO or Hybritech calibrated.

Types of PSA Tests

Some of the PSA in the blood is bound to enzymes (complexed) while some is freely circulating (free). Unless otherwise noted, the PSA levels generally refer to total PSA (or tPSA), a combination of complexed and free PSA.

Free-PSA or fPSA refers to the percentage of PSA in the blood that is not bound to enzymes. Doctors are now recommending further testing for men with a free-PSA of less than 25 percent. This is a helpful indicator for men who may be uncertain whether to get a biopsy, such as those with PSA levels between 4 and 10, and negative DRE results.

Complexed PSA or cPSA refers to the measure of one type of bound or complexed PSA. This measure is as accurate as total PSA and may be better at ruling out some people from further testing. Cut-off levels are different for cPSA, so make sure you know whether your PSA test is complexed or total. For example, a cPSA level of 2.2 is equivalent to the cut-off level of tPSA at 2.5.

PSA and Recurring Prostate Cancer

The PSA test is also used to detect and monitor recurrence of prostate cancer after initial treatment. PSA levels should drop dramatically after initial treatment. If they rise again, they are a good indicator that the initial treatment did not catch all the cancer cells.

Source: Zero: The Project to End Prostate Cancer http://www.zerocancer.org/site/PageNavigator/PSA_Test