Study Published in Journal of Clinical Oncology Finds that the Decipher® Prostate Cancer Test Predicts which Patients Benefit from Radiation Therapy Following Prostate Surgery

SAN DIEGO, Feb. 9, 2015 /PRNewswire/ -- GenomeDx Biosciences today announced the publication of a positive validation study for the Decipher^® Prostate Cancer Classifier, a genomic test for prostate cancer. The study, published in the Journal of Clinical Oncology, showed that patients with low genomic risk (as determined by Decipher) may be optimally managed with observation after radical prostatectomy (prostate surgery), while those with high genomic risk (as determined by Decipher) may be better managed earlier with adjuvant radiotherapy. The identification of the right patients for post-operative radiation therapy and the timing of administering that therapy are not easily answered by clinical risk factors alone. The study, conducted by researchers from Thomas Jefferson University and Mayo Clinic, was published online today. This is the eighth publication of a positive validation study for the Decipher Prostate Cancer test.

"The optimal timing of post-prostatectomy radiation therapy is a subject of debate," says Robert Den, M.D., of the Sidney Kimmel Medical College of Thomas Jefferson University and lead author of the study. "Common practice is to wait for prostate-specific antigen (PSA) rise after surgery before intervening with radiation treatment. The results of this study suggest that we can use a genomic test to identify a group of men who will benefit from earlier administration of additional local treatment."

Current clinical practice guidelines from the American Urological Association (AUA) and the American Society for Radiation Oncology (ASTRO) recommend physicians offer adjuvant radiotherapy after surgery for men who have been diagnosed with intermediate and high-risk prostate cancer. These recommendations are based on evidence from multiple randomized clinical trials, which demonstrated the efficacy of earlier, or adjuvant radiotherapy with reductions in recurrence and progression as compared to a "wait-and-see" approach after surgery. However, not all men receive a benefit from early radiation therapy, and there is an obvious need to identify patients who will and won't benefit, so as to avoid overtreatment and serious side effects such as incontinence, impotence, and rectal bleeding.

According to the AUA, adjuvant radiation therapy is administered because of adverse pathology after radical prostatectomy, while salvage radiation therapy refers to initiation of radiation therapy only after PSA rise, commonly referred to as biochemical recurrence. Until now, clinicians have used pathology and clinical risk factors, which are less accurate measures of metastatic risk, to select men appropriate for treatment with radiation therapy.

The introduction of Decipher into clinical practice means that physicians are now equipped with a tool that allows them to individualize management and better identify those who may actually benefit from early radiation and those who may safely delay treatment and avoid adverse side effects. Recently, the American Society of Clinical Oncology (ASCO) guidelines endorsed the AUA recommendation, but caveat that "not all men with adverse pathology are at equal risk for recurrence." The National Comprehensive Cancer Network prostate cancer guidelines further recommend "tumor-based molecular assays to better stratify patient risk" and selection of adjuvant therapy.

"We've known Decipher's prognostic capability from earlier research, and with this research, we were able to demonstrate that there's a predictive component as well," says R. Jeffrey Karnes, M.D., associate professor and vice chair in Urology at Mayo Clinic and an investigator on the study. "Determining the right patient and the right time for radiation therapy is not straightforward. Patients have to balance the potential complications from radiation treatment with the risk of prostate cancer recurring. This test may enhance our ability in deciding who should or should not be considered for adjuvant radiation versus close monitoring."

The study, entitled, "A Genomic Classifier Identifies Men with Adverse Pathology after Radical Prostatectomy Who Benefit from Adjuvant Radiation Therapy," included 188 prostate cancer patients who received radiation therapy after prostate surgery at Thomas Jefferson University and Mayo Clinic between 1990 and 2009. Decipher validated as the top risk factor for metastasis with 83% accuracy for predicting metastasis and stratifying patients with low, average, and high genomic risk with 0%, 9%, and 29% five-year cumulative incidence of metastasis (p=0.002).

The study found that Decipher may predict benefit from radiation therapy: patients with average-to-high Decipher risk who were treated with the more aggressive adjuvant radiation therapy had a five-year metastasis incidence of only 6% compared to 23% (p=0.008) for those who waited for PSA recurrence to trigger initiation of salvage therapy. Overall, patients with higher Decipher results who received adjuvant radiation had an 80% reduction in risk of metastasis compared to those who received salvage radiation (HR: 0.20, 95% CI, p<0.04). In addition, the study found no disadvantage for salvage therapy in men with low-risk Decipher results, suggesting that these men may improve quality of life by waiting for possible PSA rise rather than taking a course of immediate radiation therapy after radical surgery.

Mayo Clinic has a financial interest in the technology referenced in this news release.

About Decipher
The Decipher® Prostate Cancer Classifier is a highly validated and commercially available genomic test for men with intermediate and high risk prostate cancer. Decipher predicts cancer aggressiveness by looking for a unique genomic signature comprised of a validated series of biomarkers associated with metastatic disease. Adding truly unique information to the treatment decision-making process, Decipher generates a risk result that is completely independent and distinct from PSA, Gleason score and other clinical risk factors. Clinical studies from leading cancer centers published in over a dozen medical journals demonstrate that Decipher can accurately predict metastatic disease, which men may benefit from radiation therapy following prostate surgery, and can lead to significant cost-savings for healthcare systems. Decipher was developed in partnership with the Mayo Clinic.

Decipher is covered by Medicare and multiple private insurance plans and is available to eligible US patients through their physicians.

Learn more at: www.DecipherTest.com.

About GenomeDx Biosciences
GenomeDx Biosciences is focused on transforming cancer patient care by putting usable genomic information in the hands of patients and their physicians. GenomeDx is developing and commercializing Decipher®, a highly validated genomic test for predicting metastatic disease in men with prostate cancer.  In partnership with leading medical centers, the company has assembled the largest genomic catalogue of prostate cancer tumors in the world, representing billions of data points and more than 20 years of prostate cancer research expertise. Using advanced cloud-based bioinformatics, GenomeDx mines the genomic data to develop proprietary tests that address key clinical questions in cancer patient management. GenomeDx has partnered to share genomic data with leading clinician-scientists worldwide to collaboratively enrich the knowledge and understanding of urologic cancers for the goal of improving global cancer patient care. GenomeDx is based in San Diego, California and Vancouver, British Columbia.

Learn more at: www.GenomeDx.com.

About Jefferson 
Thomas Jefferson University, Thomas Jefferson University Hospitals and Jefferson University Physicians are partners in providing the highest-quality, compassionate clinical care for patients, educating the health professionals of tomorrow, and discovering new treatments and therapies that will define the future of healthcare. Thomas Jefferson University enrolls more than 3,600 future physicians, scientists and healthcare professionals in the Sidney Kimmel Medical College (SKMC); Jefferson Schools of Health Professions, Nursing, Pharmacy, Population Health; and the Graduate School of Biomedical Sciences, and is home of the National Cancer Institute (NCI)-designated Sidney Kimmel Cancer Center. Jefferson University Physicians is a multi-specialty physician practice consisting of over 650 SKMC full-time faculty. Thomas Jefferson University Hospitals is the largest freestanding academic medical center in Philadelphia. Services are provided at five locations — Thomas Jefferson University Hospital and Jefferson Hospital for Neuroscience in Center City Philadelphia; Methodist Hospital in South Philadelphia; Jefferson at the Navy Yard; and Jefferson at Voorhees in South Jersey.

About Laboratory Medicine and Pathology at Mayo Clinic
The Mayo Clinic Department of Laboratory Medicine and Pathology and its reference laboratory, Mayo Medical Laboratories (MML), provide advanced laboratory testing and pathology services to support 4,000 health care organizations around the world. Revenue from this testing is used to support medical education and research at Mayo Clinic, a nonprofit worldwide leader in medical care, research, and education for people from all walks of life. Complemented by collaborations with diagnostic and biotechnology companies, the department maintains a robust diagnostic test-development program, launching more than 150 new tests annually.

About Mayo Clinic 
Mayo Clinic is a nonprofit organization committed to medical research and education, and providing expert, whole-person care to everyone who needs healing. For more information, visit http://www.mayoclinic.org/about-mayo-clinic or http://newsnetwork.mayoclinic.org/.

Media Contact:
Ian Stone
Canale Communications
619-849-5388
[email protected]

SOURCE GenomeDx Biosciences

Related Links

http://www.GenomeDx.com