The PSA test is a simple blood test that is Often used as a screening test to detect the presence of a swollen prostate gland and of prostate cancer. Although the test cannot by itself be used for diagnosis it is a good indicator and, in combination with other screening tests, PSA test can suggest the need for additional investigation.

The PSA test is generally recommended for men at particular risk (such as those with a family history of prostate cancer) once they reach the age of about 40 to 45 and for men in general over 50 years of age.

An isolated test will provide a snapshot of of the level of prostate specific antigen in the blood and may indicate a problem immediately if you record a particularly high PSA score. However, in most cases, and where a prostate problem is in its initial stages of development, a single test result will prove to be inconclusive and another test will usually be suggested in a few weeks time. In fact, if possible testing should be carried out regularly 2 or 3 times every year so that PSA levels may be seen over time.

As long as you register a normal PSA score then all is fine, but as soon as your PSA levels begin to rise they have to be watched closely. The speed with which PSA levels increase is normally called the 'PSA velocity' and as long as the rise is gradual and the velocity slow then it is again often sufficient just to monitor the situation as various things can influence levels of PSA and evidently increasing levels will often be seen to fall back to normal given time.

However, where PSA readings start to increase rapidly and the velocity is said to be high then further investigation is required.

This pattern of PSA testing and monitoring has been undertaken for some considerable time but, despite the fact that the test has long been considered to be a good indicator of the need for additional investigation, it was not until fairly recently that we have been able to link specific PSA velocity to prostate cancer in a fashion that can indicate how aggressive prostate cancer is.

In a recent study data from 950 men with prostate cancer who had undergone either radiation treatment or surgery at four hospitals between 1988 and 2004 was analyzed.

In every case each patient had been diagnosed as suffering from aggressive prostate cancer on the basis of a single very high PSA score, an advanced stage tumor, a noticeable increase in PSA velocity during the year prior to diagnosis, the results of a biopsy showing an aggressive cancer at cellular level or a mix of two or more of these pointers.

This study also looked in detail at the post-treatment outcomes for all 950 men and found that a rapidly increasing PSA score that rose by 2 or more points in a twelve month period was the clearest indicator or an aggressive cancer.

Until now we have been able to associate increasing PSA levels with an indication of the possible presence of prostate cancer but it has been necessary to guess to some extent about whether such a cancer is likely to be aggressive and need equally aggressive treatment.

Now however we are able to say with a fair degree of certainty that where a PSA score rises by 2 or more points in a year then prostate cancer is almost certainly aggressive and needs to be treated swiftly and vigorously.