With nearly 200,000 diagnosed cases last year, prostate cancer is by far the most common type of cancer among American men.
Moreover, almost a similar number of men, who do not have cancerous tumours, undergo expensive and painful biopsies after being diagnosed with high levels of PSA (prostate-specific antigen).
Critics of the PSA test have called for its halt, citing the large number of unnecessary biopsies.
An experimental technique, which was revealed at a meeting of the American Society of Clinical Ontology last week, might be the solution to the problem.
The technique involves a blood test that examines the activity of six genes associated with prostate tumours and has the potential to significantly increase the accuracy of PSA testing. This means that each year, thousands of men could be spared the pain and expense of undergoing biopsies.
The new technique was tested in a two-year study involving a group of nearly 500 men. The group consisted of healthy men and patients known to have prostrate cancer, as well as subjects with benign prostatic hyperplasia, which is the leading cause of false positives in PSA testing.
By itself, the six-gene test had specificity over 80%, which means that the number of false positives was less than 20%. However, combined with the existing PSA test, the number of false positives fell to less than 10% — a marked and significant improvement over the 60%-70% level of accuracy that can be achieved by using only the current method of PSA testing.
Additionally, the six-gene PSA test is nearly 10 times cheaper than biopsies. This translates into a saving of nearly $2 billion per year for the U.S health care system, not to mention sparing thousands of men from the needless anxiety and worry of biopsies.