Treatment patterns and outcomes in prostate cancer patients tested with Decipher in SEER.

Abstract

e17006 Background: In 2021, national data between the Decipher 22-gene prognostic gene expression classifier (GC) for men with prostate cancer and the Surveillance, Epidemiology, and End Results (SEER) cancer registries were linked. The purpose of the work is to report on the linkage by characterizing national GC usage and its association with treatment decisions for men with prostate cancer. Methods: Patients in the SEER registries with primary prostate cancer diagnosis from 2010 to 2018 were included and linked to data from GC testing conducted between 2014 to 2020 (Veracyte, San Diego, CA). GC scores (range 0-1) and GC risk groups (low, intermediate, and high) were used for continuous and categorical analyses. Multivariable logistic regression was used to quantify the association between GC and active surveillance and watchful waiting (AS/WW) use and adverse pathology at radical prostatectomy (RP). Adverse pathology was defined as pathological grade group ≥3, pathological stage ≥pT3b, or lymph node invasion. Results: A total of 575,363 patients were eligible for analysis, of which 10,528 patients underwent GC testing (5,015 GC biopsy test, and 5,513 GC RP test). The median age was 67 for both tested and untested, but more white patients underwent testing (82% vs 76%, p < 0.001). For GC biopsy tested patients, AS/WW was highest for those with GC low risk results (41%) as compared to those with intermediate (32%) or high (17%) GC risk (p < 0.001). RP rates were lower in the tested compared to untested (25% vs. 36%, p < 0.001), and among the tested patients, RP use increased by GC risk group (19% of low, 25% of intermediate, and 34% of high GC risk, p < 0.001). A similar trend by GC risk group in management for radiation therapy was observed (13% of low, 19% of intermediate, and 29% of high GC risk, p < 0.001). In a multivariable logistic regression adjusted for age, race, NCCN risk group, and year of diagnosis, GC tested patients were more likely to undergo AS/WW compared to untested (OR 2.9 [95% CI, 2.8-3.1], p < 0.001). Within the subset of patients classified as NCCN low/favorable intermediate risk at biopsy and who were subsequently treated with RP (n = 594), GC high risk (> 0.6) was associated with more than 3 times the odds of harboring adverse pathology (OR 3.2 [95% CI 1.6-6.4], p < 0.001). Conclusions: Using the first ever linked SEER-Decipher data, we demonstrate that population-based treatment patterns are independently associated with GC test results. Patients with lower GC scores are independently more likely to undergo AS/WW; those with higher scores are more likely to have adverse pathology at time of RP.