Decipher Prostate Cancer Test Guides Timing of Postoperative Radiotherapy

SAN DIEGO, May 19, 2016 /PRNewswire/ -- GenomeDx Biosciences today announced the publication of a multi-institution validation study of the Decipher® Prostate Cancer Classifier, a genomic test for prostate cancer used to improve clinical decision-making following diagnostic biopsy or radical prostatectomy (RP). This study further validated the impact of clinico-genomic risk assessment by Decipher and CAPRA-S on metastasis outcomes for patients treated with three different postoperative radiation therapy modalities, as compared to observation alone, following RP. The data demonstrate that patients with low clinico-genomic risk, as assessed by CAPRA-S and Decipher scores, have excellent survival without any postoperative therapy and those at highest clinico-genomic risk have the best metastasis-free outcomes when treated early with adjuvant radiation therapy (ART).

"Treating prostate cancer patients according to a uniform strategy is inadequate, and can result in over- or under-treatment for many men," said lead study author Ashley Ross, M.D., Ph.D., assistant professor of urology, Johns Hopkins Medical Center. "This can result in exposing the patient to unnecessary toxicity, missing the opportunity to achieve cure as well as overburdening of the healthcare system. The findings of this study may provide patients and physicians with improved tools with which decisions could be made regarding further treatment, if any, after surgery."

The study, published this month online ahead of print in the latest issue of Prostate Cancer and Prostatic Diseases, included 422 prostate cancer patients identified from the Decipher GRID® database. These patients underwent RP between 1990-2010 at Mayo Clinic, Durham VA, Johns Hopkins Medical Institution and Thomas Jefferson University. All patients reached an undetectable prostate-specific antigen (PSA) level following surgery and either received no postoperative treatment prior to developing metastasis (n=158), or were treated with ART (n=111), minimal residual disease salvage radiotherapy (MRD-SRT, n=70), or salvage radiotherapy (SRT, n=83), defined by initiation of therapy at PSA levels of <0.2, 0.2 to 0.49 and ≥0.5 ng/mL, respectively. The men who did not receive additional therapy (including hormonal suppression) prior to metastasis formed the no radiation therapy (RT) or observation arm.

Multivariable analysis demonstrated that after adjusting for clinico-genomic risk, patients treated with SRT or who were observed with no RT had a nearly fivefold higher rate of metastasis when compared to patients that underwent ART or MRD-SRT. This suggests that delaying postoperative radiation in men with adverse pathological features and high genomic risk is unlikely to be curative and strong consideration should be given to the earlier use of postoperative radiation and the addition of systemic therapy through participation in clinical trials. Furthermore, the study showed that for men with lower clinico-genomic risk, the survival benefits from earlier radiation were modest, and that these men may be optimally managed using an active surveillance approach. Finally, these results provide Decipher users with metastasis risk estimates for postoperative ART, MRD-SRT, SRT and observation that may be of further use to guide decision-making in this setting.

"The imprecise identification of patients at highest risk of metastatic disease and death from prostate cancer highlights the need for additional risk stratification beyond the clinical features," said Doug Dolginow, M.D., chief executive officer of GenomeDx. "This study further supports the use of clinical and genomic information together to provide a more comprehensive assessment of metastatic risk. Further, it demonstrates how incorporation of the Decipher test into patient treatment plans allows for an individualized approach to the care of men with prostate cancer, which we believe results in improved patient quality of life and efficient use of healthcare resources."

About Decipher® Prostate Cancer Classifier Tests
Our Decipher prostate cancer classifier tests are currently comprised of 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 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.

Learn more at www.DecipherTest.com

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.    

Learn more at www.DecipherGRID.com

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

SOURCE GenomeDx Biosciences

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