UPDATE - Issue 22 - Summer 2005
Better than PSA?
The search for a test that is better than the PSA test for detecting prostate cancers is hotting up.
A new urine test may provide a much more effective way of detecting early prostate cancer. Researchers at John Hopkins University in Baltimore found that the test for a blood protein called EPCA, early prostate cancer antigen, can spot the disease with a 94% accuracy rate. This promising result, albeit with a relatively low number of patients, is a lot better than one would expect from the PSA test.
Yet another line of research is based on a recently discovered gene PCA3 that has been shown to be over-expressed only in malignant prostate tissue. The company developing the new urine test has evaluated it amongst over 400 men and found it to be significantly more accurate than what is currently achievable with PSA screening.
The widespread use of the PSA test has led to increased tumour detection rates, particularly among those at early stages of the disease. This has led to a clinical dilemma, since standard analysis of biopsy samples often cannot distinguish which tumours are going to spread and which are not. Many men live for years with slow-growing prostate tumours before they die of unrelated causes, and treating such patients could cause more harm than good. So finding a better way to determine which patients need aggressive treatment and which can try active surveillance has become a major challenge.
Magnetic resonance spectroscopy, which provides detailed information on the chemical composition of tissue samples, may be the answer. Researchers from Massachusetts General Hospital believe that it can determine a tumour's prognosis better than standard pathological studies. Now they wish to evaluate their techniques with a much larger sample of men.
All these new approaches show promise but all are some considerable way from clinical use. Prostate Research Campaign UK looks forward to seeing the results of larger trials. We hope they are successful and we shall certainly publicise promising results as they are reported.