Though there are various different tests which can be carried out when you suspect the possible presence of prostate cancer, the only certain way to diagnose the disease is the prostate biopsy. But precisely how successful is the biopsy when it comes to diagnosing this disease?

In the United States alone annually there are about one million prostate biopsy procedures carried out of which around 25 percent indicate the existence of cancer. Of the remaining 75 percent of biopsies however roughly 33 percent indicate false negative results. This means that about a quarter of those men undergoing a prostate biopsy are cleared by their biopsy, despite the fact that they actually have prostate cancer.

At first sight therefore it could seem that the biopsy is not a very good test but these results do not mean that there is anything wrong with the prostate biopsy procedure as a tool for diagnosing the presence of cancer. What it does mean however is the need to detect those patients who, in spite of they have returned a negative result, are nonetheless at considerable risk from cancer and ought therefore to undergo a second follow-up biopsy.

The problem is that until very recently there has not been an easy method of determining patients at risk. Fortunately, a recent study of more than five hundred men being investigated for the possible presence of prostate cancer might now provide an answer.

All of the men investigated in the study had already had a negative biopsy result but researchers discovered that when they studied the patient's prostate specific antigen (PSA) test results and these were adjusted to take account of the size of the prostate gland they could identify those patients who were more likely to produce positive results on a follow-up biopsy.

Additionally, the researchers found that patients who had a Gleeson score of 7 or above were at greater risk from life-threatening cancer and were once again more likely to record a positive result on a second biopsy. The Gleeson score runs on a scale between 2 and 10 and the score is derived from a microscopic investigation of biopsy tissue. Low scores show a cancer with a relatively small risk of spread while high scores show a cancer which is much more likely to spread.

There are various different biopsy procedures in use now but perhaps the most frequently performed procedure is known as the core needle biopsy. Here a number of very small tissue samples are removed from different areas of the prostrate gland using a biopsy gun which shoots a needle into the selected area and removes the sample within a fraction of a second. These samples are then sent off for laboratory analysis to ascertain whether or not cancer is present and, if so, to determine precisely how much of the prostate gland is affected.

The prostate biopsy is a costly procedure and is a test which can be quite nerve-racking for the patient. It can also be a fairly painful test which can be accompanied by bleeding and a risk of infection. For these reasons it is in everyone's interest to identify those men for whom a follow-up biopsy would be advisable and to reduce as far as possible the number of needless follow-up biopsies being carried out each year.