Main Session

Sep 29

PQA 06 - Genitourinary Cancer, Gynecological Cancer, and Health Care Access and Engagement

3297 - Preoperative Biopsy Genomic Classifier and Secondary Radiotherapy after Radical Prostatectomy: National Real-World Evidence

02:15pm - 03:30pm ET

Poster Hall - Exhibit Hall A

Screen: 12

POSTER

Presenter(s)

Thomas Kole, MD, PhD - Memorial Sloan Kettering Monmouth, Middletown, NJ

T. P. Kole¹, Q. Joslove Xu², A. R. Barsky¹, J. Janopaul-Naylor¹, Z. R. Moore¹, E. Bent¹, D. J. Gorovets¹, V. S. Brennan¹, S. M. McBride¹, J. Haseltine¹, D. M. Guttmann¹, M. A. Kollmeier¹, J. Setton¹, M. B. Bernstein¹, X. Zhao², A. Moradi², Y. Liu², J. Proudfoot², E. Davicioni², and H. Nagar¹; ¹Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, ²Veracyte, Inc., South San Francisco, CA

Purpose/Objective(s): Secondary radiation therapy (SRT) with or without androgen deprivation therapy (ADT) is a standard treatment for biochemical recurrence (BCR) after radical prostatectomy (RP) for localized prostate cancer (PCa). Preoperative clinical risk factors predict risk of BCR after RP and the subsequent need for SRT. We examined real-world data (RWD) to determine the impact of pre-RP prostate biopsy genomic classifier (GC) scores on the time to SRT with or without ADT in men who underwent RP for PCa.

Materials/Methods: We conducted a retrospective study of a national clinical–genomic linkage of Decipher GC with longitudinal RWD (Veracyte, South San Francisco, CA). The cohort included 21,972 patients treated with RP between 2016-2025 who had preoperative biopsy GC testing. Patients were stratified by GC group (low, intermediate, high) within NCCN clinical risk groups. Among patients who received SRT, median time to SRT with or without ADT was compared overall and within NCCN risk groups for each GC risk group using Cox proportional hazards and log-rank tests.

Results:

Among the 21,972 patients, 781 (3.6%) received ADT alone after RP and were removed from subsequent analysis. Median follow-up was 21.6 months (IQR: 8.8-39.1) for the remaining 21,191 patients, and SRT was administered in 7% of cases (n = 1,480), including 645 with ADT. In the subset of patients who received SRT, median time to SRT was 9.7 months (IQR: 5.4-20.5). GC scores were classified as low, intermediate, or high in 24.7%, 13.7%, and 61.6% of patients receiving SRT, respectively.

Administration of SRT following RP was associated with increasing GC score across all NCCN risk groups except low risk (p<0.001). GC-high versus GC-low was most discriminatory in unfavorable intermediate risk (UIR) (HR=2.47, 95% CI 2.02-3.02, p<0.001), and demonstrated significance in favorable intermediate risk (FIR) (HR=1.78, 95% CI 1.32-2.40, p<0.001), high risk (HR) (HR=2.25, 95% CI 1.68-3.02, p<0.001), and very high risk (VHR) patients (HR=2.10, 95% CI 1.09-4.02, p<0.05). Concurrent ADT utilization also increased with GC risk: 30.6% in GC-low vs 48.8% in GC- high (p<0.001).

Among patients who received SRT, median time from RP to SRT decreased with higher GC score across all NCCN risk groups. For NCCN low risk patients: 14.1, 22.1, and 11.4 months for GC low, intermediate, and high, respectively; FIR: 14.7, 11.6, and 12.9 months; UIR: 13.9, 11.5, and 10.0 months; HR: 11.3, 9.1, and 7.1 months; and VHR: 19.0, 5.3, and 5.2 months.

Conclusion: Among patients treated with RP for PCa, higher preoperative biopsy GC score was associated with increased administration and decreased time to SRT. Biopsy GC score was most associated with SRT in patients with NCCN FIR to HR disease and was also associated with ADT utilization. GC score may be a useful tool to guide primary treatment decision at the time of PCa diagnosis.