The Decipher genomic classifier (GC) is increasingly being used to determine metastasis risk in men with localized prostate cancer (PCa). Whether GCs predict for the presence of occult metastatic disease at presentation or subsequent metastatic progression is unknown.
To determine if GC scores predict extraprostatic 68Ga prostate-specific membrane antigen (68Ga-PSMA-11) positron emission tomography (PET) positivity at presentation.
Between December 2015 and September 2018, 91 PCa patients with both GC scores and pretreatment 68Ga-PSMA-11 PET scans were identified. Risk stratification was performed using the National Comprehensive Cancer Network (NCCN), Cancer of the Prostate Risk Assessment (CAPRA), and GC scores.
Logistic regression was used to identify factors correlated with PSMA-positive disease.
The NCCN criteria identified 23 (25.3%) and 68 patients (74.7%) as intermediate and high risk, while CAPRA scores revealed 28 (30.8%) and 63 (69.2%) as low/intermediate and high risk, respectively. By contrast, only 45 patients (49.4%) had high-risk GC scores. PSMA-avid pelvic nodal involvement was identified in 27 patients (29.7%). Higher GC score was significantly associated with pelvic nodal involvement (odds ratio [OR] 1.38 per 0.1 units; p=0.009) and any PSMA-avid nodal involvement (pelvic or distant; OR 1.40 per 0.1 units; p=0.007). However, higher GC score was not significantly associated with PSMA-avid osseous metastases (OR 1.11 per 0.1 units; p=0.50). Limitations include selection bias for patients able to receive both tests and the sample size.
Each 0.1-unit increase in GC score was associated with an approximate 40% increase in the odds of PSMA-avid lymph node involvement. These data suggest that patients with GC high risk might benefit from more nodal imaging and treatment intensification, potentially via pelvic nodal dissection, pelvic nodal irradiation, and/or the addition of chemohormonal agents.
Patients with higher genomic classifier scores were found to have more metastatic lymph node involvement on prostate-specific membrane antigen imaging.
European urology oncology. 2019 Jan 14 [Epub ahead of print]
Melody J Xu, Zachary Kornberg, Adam J Gadzinski, Dongmei Diao, Janet E Cowan, Susan Y Wu, Lauren Boreta, Daniel E Spratt, Spencer C Behr, Hao G Nguyen, Matthew R Cooperberg, Elai Davicioni, Mack Roach, Thomas A Hope, Peter R Carroll, Felix Y Feng
Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA., Department of Urology, University of California San Francisco, San Francisco, CA, USA., Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA; Department of Surgical Oncology, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China., Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA., Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA., GenomeDx Inc., San Diego, CA, USA., Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA; Department of Urology, University of California San Francisco, San Francisco, CA, USA. Electronic address: .