GenomeDx's Decipher GRID Aids in Development and Validation of the First Molecular Signature to Predict Response to Radiotherapy in Prostate Cancer

SAN DIEGO, Oct. 19, 2016 /PRNewswire/ -- GenomeDx Biosciences today announced that gene expression profiles in the company's Decipher Genomics Resource Information Database (Decipher GRID®) were used in the discovery of Post-Operative Radiation Therapy Outcomes Score (PORTOS), the first validated molecular signature developed to predict patients' response to radiotherapy in prostate cancer. A study validating the molecular signature, titled "Development and validation of a 24-gene predictor of response to postoperative radiotherapy in prostate cancer: a matched, retrospective analysis," was published online this month ahead of print in The Lancet Oncology.

In the study, researchers used Decipher GRID to develop and validate the PORTOS 24-gene expression signature that predicts response to postoperative radiotherapy in patients with prostate cancer. The data demonstrates that patients with high PORTOS scores treated with radiotherapy had a lower incidence of distant metastasis at 10 years than patients with high PORTOS scores who did not receive radiotherapy, suggesting that treatment with postoperative radiotherapy should be considered for patients in this subgroup. Conversely, patients with low PORTOS scores had similar outcomes whether or not they received postoperative radiotherapy.

The retrospective study used to identify the 24-gene expression signature included a training cohort of 196 prostate cancer patients who received radical prostatectomy with or without postoperative radiotherapy. The signature was designed to enrich for intrinsic radiation response using genes that are related to radiation or DNA damage response. The signature was validated in a multi-institutional cohort consisting of 330 patients, in which PORTOS was shown to have a significant correlation of score and radiation treatment, confirming the predictive value of PORTOS for radiation response.

"Although prognostic signatures have become widely established in prostate cancer research, the development of signatures that can predict response to individual therapies has been a difficult proposition," said Felix Feng, M.D., associate professor of radiation oncology, urology and medicine at the University of California, San Francisco. "The development of PORTOS may help physicians predict which patients will benefit most from postoperative radiotherapy, improving patient selection while reducing unnecessary toxicity in those who would not benefit significantly from treatment."

Gene signatures have been used in various cancer types to develop prognostic and predictive tools that allow clinicians to direct therapeutic agents to patients likely to benefit most. Currently, the widely used genomic and clinical risk tools for prostate cancer are prognostic in nature. These tests can identify which patients have aggressive disease and presumably need intensification of therapy, but not which type of therapy should be given.

"Ultimately, we envision the field moving towards a biomarker-driven approach whereby prognostic signatures identified through the use of a genomic test, such as Decipher®, are used to select patients with aggressive disease, and predictive signatures, such as PORTOS, are used to select specific therapies," said Doug Dolginow, M.D., chief executive officer of GenomeDx. "We believe this work will improve the personalization of therapy for patients with prostate cancer."

The PORTOS signature is currently available on the Research Use Only GRID Tumor RNA Expression Profile, which is available to physicians who have ordered the Decipher Prostate Cancer Classifier test.

About Decipher® Prostate Cancer Classifier Tests
Our Decipher Prostate Cancer Classifier tests currently include Decipher Biopsy and Decipher Post-Op. These commercially available genomic tests provide an assessment of tumor aggressiveness based on the patient's unique genomic profile. Decipher Biopsy is indicated for men with localized prostate cancer after biopsy diagnosis and Decipher Post-Op is indicated for men after prostate removal surgery. The Decipher tests are used by physicians to stratify patients into more accurate risk groups to better determine which patients will likely benefit from additional treatment and which will not, thereby enabling improved decision-making and helping low-risk patients avoid unnecessary treatments that have serious adverse side effects and result in unnecessary costs to the healthcare system. Studies of thousands of patients from leading cancer centers, published in multiple peer-reviewed journals, demonstrate that the Decipher tests can more accurately predict disease aggressiveness than traditional clinical measures, such as PSA and Gleason score. Decipher Post-Op is covered by Medicare and by a number of private payors and preferred provider organizations representing, together with Medicare, about 70% of the approximately 66 million adult men in the United States age 40 or older who are at increased risk of being diagnosed with prostate cancer.

About Decipher GRID®
Our Decipher Genomics Resource Information Database (Decipher GRID) is a genomic expression database that provides a foundation for open and interactive research collaboration and knowledge creation. Decipher GRID is a rapidly growing database that contains genomic profiles of thousands of patient tumors, and constitutes what we believe to be the world's largest shared, clinically-annotated genomic expression database in urologic cancer as well as one of the world's largest global RNA expression databases utilizing cloud-based analytics. We believe Decipher GRID gives rise to new opportunities for information technology-enabled genomic solutions and enables us to more rapidly discover, develop, commercialize and drive the adoption of our existing and new genomic tests. Through Decipher GRID, GenomeDx is building a suite of genomic tests in urologic cancer that we believe will allow us to achieve our goals of reducing costs to the healthcare system and improving patient lives, from screening through late-stage therapy.

About GenomeDx Biosciences
GenomeDx Biosciences uses the power of collaborative genomics to transform the management and treatment of cancer patients. GenomeDx has built Decipher GRID, a large genomics database in urologic cancer that provides a foundation for open and interactive research collaboration and knowledge creation. Using Decipher GRID to analyze vast amounts of genomic data, GenomeDx develops and commercializes proprietary clinical tests that are intended to provide more accurate and useful diagnostic information than both traditional diagnostic tools and existing genomic tests. GenomeDx's Decipher Biopsy and Decipher Post-Op are commercially available prostate cancer genomic tests that provide an assessment of tumor aggressiveness based on a patient's unique genomic profile. GenomeDx is headquartered in Vancouver, British Columbia and has offices in San Diego, California.

Learn more at www.GenomeDx.com

UC Disclaimer
The information stated above was prepared by GenomeDX Biosciences and reflects solely the opinion of the corporation. Nothing in this statement shall be construed to imply any support or endorsement of GenomeDX, or any of its products, by The Regents of the University of California, its officers, agents and employees.

SOURCE GenomeDx Biosciences

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