Genomic Scores are Independent of Disease Volume in Men with Favorable Risk Prostate Cancer: Implications for Choosing Men for Active Surveillance

To determine if disease volume at prostate biopsy correlates with genomic scores among men with favorable risk prostate cancer.All men with NCCN very low (VLR) and low risk (LR) disease and OncotypeDx Prostate testing at our institution from 2013 to 2016 were identified. Volume of disease was characterized as percent of positive cores, number of cores with >50% involvement, largest involvement of any single core, and PSA density. Nonparametric testing was performed to compare the median genomic prostate score (GPS) and likelihood of favorable pathology (LFP) between quartiles of disease volume.112 (37.8%) and 184 (62.2%) NCCN VLR and LR men were identified, respectively. Median GPS scores did not differ significantly between disease volume quartiles (all p > 0.05); however, median LFP was statistically different between volume quartiles (all < 0.05). In total, 7/105 (6.3%) of men with VLR disease were reclassified to LR, and 13/181 (7.2%) with LR disease were reclassified as intermediate risk. Genomic disease reclassification was not dependent on biopsy tumor volume.For patients with NCCN VLR and LR risk prostate cancer, genomic scores did not demonstrate meaningfully significant differences by volume based on clinically established cutpoints. Moreover, genomic scores identified and reclassified men with higher risk disease despite generally acceptable surveillance characteristics in this group by grade and volume. This suggests that for low risk patients, the tumor's biologic potential as measured by genomics, rather than volume, should inform decisions on active surveillance candidacy.