New Early Detection Test for Prostate Cancer
Test looks for cancer markers as well as PSA (September 25)
More than 1 million men will undergo a prostate biopsy this year, but only about 20% of those biopsies will result in a cancer diagnosis.
The reason is that the traditional prostate cancer screening test — a blood test to measure prostate specific antigen (PSA) — does not give doctors a complete picture, say researchers at the University of Michigan.
The investigators have begun offering a new urine test called the Mi-Prostate Score (MiPS) to improve on PSA screening for prostate cancer. The test incorporates three specific markers that could indicate cancer, and studies have shown that the combination is far more accurate than PSA alone.
The researchers validated the new test on nearly 2,000 urine samples. MiPS was significantly more accurate than PSA alone for predicting cancer as well as for predicting aggressive prostate cancer that is likely to grow and spread quickly.
MiPS was developed from a discovery in 2005 of a genetic anomaly that occurs in about half of all prostate cancers — an instance of two genes changing places and fusing together. This gene fusion — T2:ERG — is believed to cause prostate cancer. Studies in prostate tissues have shown that the gene fusion almost always indicates cancer.
The new urine test looks for the T2:ERG fusion as well as for another marker, PCA3. These are combined with the serum PSA measure to produce a risk assessment for prostate cancer. The test also predicts the risk of having an aggressive tumor, helping both physicians and patients make decisions about whether to wait and monitor test levels or to pursue immediate biopsy.
Source: University of Michigan; September 25, 2013.