The PSA test is a simple blood test that is frequently performed to screen for the presence of benign enlargement of the prostate gland and of prostate cancer. Desite the fact that the test cannot by itself be used for diagnosis it is a good indicator and, together with other screening tests, PSA test can suggest the need for further investigation.

PSA testing is generally recommended for men at particular risk (like those with a family history of prostate cancer) once they reach the age of around 40 to 45 and for all men after they reach 50.

An isolated PSA test will provide a snapshot of prostate specific antigen levels in the blood and might indicate a problem straight away if you have especially high psa numbers. However, in most cases, and where a prostate problem may be in its early stages of development, an isolated PSA test result will prove to be inconclusive and a further test will normally be suggested a few weeks later. Indeed, if possible PSA testing ought to be carried out regularly 2 or 3 times every year so PSA levels may be seen over time.

As long as you register a normal PSA score then all is well, but when your PSA scores start to increase they have to be monitored closely. The speed at which PSA scores increase is usually referred to as the 'PSA velocity' and if the increase is gradual and the velocity slow then it is again often enough just to monitor the situation as numerous things can influence PSA levels and evidently rising levels will often be seen to return to normal in time.

However, when PSA test readings start increasing rapidly and the velocity is high then further investigation is required.

PSA testing and monitoring has been performed for some time but, although the test has long been thought of as a good indicator of the need for further investigation, it was not until fairly recently that we have been in a position to link specific PSA velocity figures to prostate cancer in a fashion that can indicate the aggressiveness of a cancer.

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

In all cases the patients had been diagnosed as suffering from aggressive prostate cancer on the basis of an isolated very high PSA reading, the presence of an advanced stage tumor, a noticeable increase in PSA velocity in the year before diagnosis, the results of a biopsy indicating an aggressive cancer at cellular level or a mixture of two or more of these signs.

The study also looked at the outcomes for all of the patients and discovered that a rapidly rising PSA level that rose by 2 points or more in a twelve month period was the clearest indicator or the presence of an aggressive cancer.

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

Now however we can say with relative certainty that where a PSA level rises by 2 or more points in a year then prostate cancer is almost certainly aggressive and requires quick and vigorous treatment.