New data validating the clinical utility of the Decipher prostate genomic classifier for guiding treatment selection in men with intermediate-risk prostate cancer was presented at the 2022 ASCO Genitourinary Cancers Symposium (Abstract 269). Data from the randomized phase III NRG/RTOG 0126 study, confirm initial findings that the genomic test provides prognostic biomarker information that can help physicians and patients make personalized treatment decisions in the intermediate-risk setting.
“These findings represent the first high-level evidence of any genomic classifier in intermediate-risk prostate cancer and demonstrate that the Decipher 22-gene biomarker significantly improves prognostic performance across numerous clinically meaningful endpoints,” said lead investigator for the study Daniel Spratt, MD, Chair of Radiation Oncology at University Hospitals Seidman Cancer Center and Professor and Chair of the Department of Radiation Oncology at Case Western Reserve University School of Medicine.
These findings represent the first high-level evidence of any genomic classifier in intermediate-risk prostate cancer and demonstrate that the Decipher 22-gene biomarker significantly improves prognostic performance across numerous clinically meaningful endpoints.— Daniel Spratt, MD
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Prostate cancer deemed intermediate-risk by the National Comprehensive Cancer Network (NCCN) Guidelines® for Prostate Cancer is the most heterogeneous of all risk groups in prostate cancer, and there are a wide variety of treatment options available. The Decipher prostate genomic classifier is a prognostic biomarker that provides additional information about the aggressiveness of individual patients’ cancer to help physicians more accurately categorize their risk and select appropriate treatments. The study conducted by Dr. Spratt and colleagues confirms findings from prior phase II studies and validates—for the first time—the test’s performance in men with intermediate-risk disease using multicenter phase III trial data.
Prognostic Performance Measured in Samples From NRG/RTOG 0126
To assess the prognostic performance of the Decipher prostate test in the intermediate-risk, postbiopsy setting, researchers utilized patient biopsy samples from the phase III randomized NRG/RTOG 0126 trial. This study enrolled men with intermediate-risk prostate cancer, and then compared clinical outcomes following random assignment to two different doses of radiation therapy (70.2 Gy vs 79.2 Gy) without hormone therapy. Researchers generated classifier data for each of 215 biopsy samples, then linked the data with clinical outcomes assessing multiple oncologic and survival endpoints. Patients were followed for a median of 12.8 years.
The findings showed that the Decipher prostate test was independently prognostic for all clinical endpoints, including disease progression (subdistribution hazard ratio [sHR] = 1.12, 95% confidence interval [CI] = 1.0–1.26, P = .04), biochemical failure (sHR = 1.22, 95% CI = 1.1–1.37, P < .001), distant metastasis (sHR = 1.28, 95% CI = 1.06–1.55, P = .01), prostate cancer–specific mortality (sHR = 1.45, 95% CI = 1.2–1.76, P < .001), distant metastasis–free survival (sHR = 1.12, 95% CI = 1.03–1.23, P = .009), and overall survival (sHR = 1.11, 95% CI = 1.01–1.21, P =.03).
Men in the study with disease classified as high-risk on Decipher had worse 10-year oncologic and survival outcomes compared to those whose disease was classified as Decipher low-risk. Based on this finding, men with intermediate-risk prostate cancer whose disease is classified as Decipher high-risk may have improved outcomes with treatment intensification (ie, the addition of hormone therapy), whereas men with disease classified as Decipher low-risk may have favorable outcomes with radiotherapy alone.
The study also evaluated—within Decipher risk groups—the clinical impact of receiving lower- vs higher-dose radiation. Among patients with lower Decipher risk scores, the difference in 10-year distant metastasis rates between those who received 70.2 Gy vs 79.2 Gy of radiation was low (5%). However, among those with higher Decipher scores, the difference was 26%, suggesting that men whose disease is Decipher high-risk receive more benefit from the higher dose of radiation than their lower-risk counterparts.
Informing Treatment in Asian Men With Prostate Cancer
In a second presentation at the ASCO Genitourinary Cancers Symposium (Abstract 273), researchers shared data from a study that evaluated the clinical utility of the Decipher prostate genomic classifier in Asian men with prostate cancer, as well as the genomic differences between prostate cancer in Asian vs Caucasian men enrolled in an 80,829-patient cohort.
In a retrospective analysis of Asian men treated at the National Cancer Centre of Singapore, researchers found that high-risk Decipher scores were significantly associated with worse metastasis-free survival (hazard ratio = 5.22, 95% CI = 1.08–25.3, P = .04). Additionally, the study found substantial differences in tumor biology between Asian and White men with prostate cancer.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
