A newly published study of a novel molecular diagnostic test by Myriad Genetics Inc, Salt Lake City, has demonstrated that the test can accurately predict which men will develop biochemical recurrence or metastatic disease following radical prostate surgery.

Published ahead of print in the Journal of Urology, the study examined the performance of Myriad’s Prolaris, a 46-gene molecular diagnostic test that has been evaluated in more than 5,000 patients across 11 clinical studies. Results of the new study showed that the Prolaris test predicts metastases in prostate cancer based on biopsy specimens.

Bishoff

Jay Bishoff, MD, Intermountain Health Care

“This study represents a great advance in the treatment of prostate cancer. The results from three different institutions show that Prolaris can better define patient prognosis and improve care,” said Jay T. Bishoff, MD, a study investigator and director of the Intermountain Urological Institute at Intermountain Health Care. “Having a test that identifies which patients are likely to fail surgery is a big clinical advantage for physicians. Patients with a low score may be candidates for active surveillance, while patients with a high score indicative of aggressive cancer may benefit from more intensive medical treatments.”

Prolaris is an RNA-expression test that directly measures tumor cell growth characteristics for stratifying the risk of disease progression in prostate cancer patients. The test provides a quantitative measure of the RNA expression levels of genes involved in the progression of tumor growth. Low gene expression is associated with a low risk of disease progression in men who may be candidates for surveillance; high gene expression is associated with a higher risk of disease progression in patients who may benefit from additional therapy.

The study evaluated biopsy specimens in 582 men who were treated by radical prostatectomy. In the study, biopsy samples were evaluated from three cohorts of contemporary patients in the United States and Germany. The clinical endpoints were metastatic disease and biochemical recurrence (BCR). In all cohorts, the Prolaris test was a statistically significant predictor of BCR and was the single strongest predictor of metastatic disease when compared to Gleason Score or PSA. In the pooled analysis, each one-unit increase in the Prolaris score translated into a fivefold increased risk of metastases and a 1.6-times increased risk of BCR.

Brawer

Michael Brawer, MD, Myriad Genetic Laboratories

“Men newly diagnosed with prostate cancer are often treated by radical prostatectomy, and about 30% of these patients will have metastases or progress even after surgery,” said Michael Brawer, MD, vice president for medical affairs at Myriad Genetic Laboratories. “The Prolaris test answers an important clinical question for all urologists concerning their surgical candidates—do my patients have an aggressive prostate cancer or not and therefore need more aggressive treatment?”

For additional information, visit Myriad Genetics Inc.