Last year GenomeDx Biosciences presented data showing that its Decipher® Prostate Cancer Classifier (the test), a genomic test, is capable of predicting the probability that a man will eventually develop metastatic prostate cancer, despite having surgery as a primary treatment for prostate cancer. The company claims that the test out performs other existing tests of clinical risk factors for predicting biochemical failure and the development of distant metastasis following primary surgery. In addition, researchers observed significant improvement in outcomes of those men with high risk Decipher results who received adjuvant radiation therapy earlier rather than later after surgery.
The data was presented at the 2014 American Society of Clinical Oncologists (ASCO) Genitourinary Symposium.
“This is the first validation of the Decipher test in patients receiving radiation therapy following prostate surgery,” said Dr. Adam Dicker, MD PhD, Chair of Radiation Oncology at the Kimmel Cancer Center. “Decipher improved the ability to predict men at risk for biochemical failure and distant metastasis after postoperative radiotherapy over and above existing clinical risk factors such as Gleason score, tumor stage and PSA. These data indicate that patients with a high Decipher result may benefit from earlier radiation and a multi-modal approach to treatment.”
Decipher was evaluated using a sample of 139 men who had undergone radiation therapy after prostatectomy at Thomas Jefferson University between 1990 and 2009. Researchers extracted RNA (a type of genetic material) from the preserved tissue samples and run on the Decipher test. Patient histories were then analyzed to determine if Decipher was able to stratify patients who could have benefited from earlier radiation therapy.
In the men identified as high risk by the Decipher test, those that received early radiation therapy survived for a median of eight years without biochemical failure, defined as an increase in their PSA post surgery. This was compared to less than four years for those men that received later radiation therapy. At eight years following radiation therapy, high risk Decipher patients who had received early radiation therapy had a three percent cumulative incidence of metastasis versus 23 percent for those men with high risk Decipher results that got late radiation therapy.
“The findings of our study have ramifications for many of the current ongoing clinical trials evaluating post prostatectomy radiation therapy,” noted Dr. Robert Den, MD, Radiation Oncologist at Kimmel Cancer Center and lead author of the study. “They suggest that there is a subset of patients who would benefit from immediate treatment and those who can afford to postpone therapy.”
Since the presentation of this data there has been a number of additional studies which have evaluated over 1,800 men. These studies have validated the presented data.
Decipher measures 22 genomic biomarkers associated with metastatic prostate cancer. It generates a result that indicates the likelihood of a man developing metastasis after primary treatment. The result is completely independent of PSA and other existing clinical variables.
Decipher should become a standard part of any early prostate cancer treatment protocol for thsoe men who have primary surgery to treat prostate cancer.
Source: GenomeDx Biosciences