Every year there are about one million prostate biopsies carried out in the United States alone, of which about 25 percent show the presence of prostate cancer. However, another 25 percent of these biopsies also produce false negative results, which means that a quarter of those men undergoing a prostate biopsy are being cleared by their biopsy, despite the fact that they do in fact have prostate cancer.
These results do not means that there is anything wrong with the prostate biopsy procedure as a tool for identifying prostate cancer, but it does mean that there is a need to identify those patients who, despite returning a negative result, are at high risk from prostate cancer and should therefore undergo a second follow-up biopsy.
Until now there has been no simple way of identifying patients at risk, however, a recent study of more than 500 patients being investigated for prostate cancer may provide a solution.
All of the men in the study group had previously received a negative biopsy result and researchers found that when they looked at both a patient’s prostate specific antigen (PSA) test results and adjusted this for the size of the prostate gland they were able to identify those patients who were more likely to receive a positive result on a follow-up biopsy.
The researchers also discovered that a Gleeson score of 7 or higher suggested the presence of a life-threatening prostate cancer and the need for a further biopsy. The Gleeson score, which runs on a scale between 2 and 10, is derived from a microscopic investigation of biopsy tissue, with a low score indicating a cancer with a low risk of spread and a high score indicating a cancer which is more likely to spread.
A prostate biopsy is an expensive procedure and one which can also be very worrying for the patient. It can also be a painful procedure which can be accompanied by bleeding and patients run the risk of infection following the biopsy. For these reasons it is in everyone’s interest to identify those patients for whom a second biopsy is advisable and to reduce as far as possible the number of unnecessary follow-up biopsies being performed each year.
