Association Between Oncotype DX Genomic Prostate Score and Adverse Tumor Pathology After Radical Prostatectomy

Abstract

Background: The Oncotype DX assay is a clinically validated 17-gene genomic assay that provides a genomic prostate score (GPS; scale 0-100) measuring the heterogeneous nature of prostate tumors. The test is performed on prostate tissue collected during biopsy. There is a lack of data on the association between the GPS and tumor pathology after radical prostatectomy (RP).

Objective: To investigate the association between GPS and final pathology, including extraprostatic extension (EPE), positive surgical margin (PSM), and seminal vesicle invasion (SVI).

Design, setting, and participants: Data for the 749 patients who underwent Oncotype DX assay and RP at a referral prostate cancer center between 2015 and 2019 were retrospectively assessed to evaluate the association between GPS and unfavorable pathology parameters.

Intervention: After a GPS genetic test, patients underwent robotic RP performed by the same surgeon.

Outcome measurements and statistical analysis: Multivariable logistic regression analyses were performed to assess the association between GPS and EPE, PSM, and SVI. The models were adjusted for age, clinical stage, prostate-specific antigen (PSA) level, Gleason score, and time between the genomic assay and surgery. The median time between Oncotype DX assay and surgery was 176 d (interquartile range [IQR] 141-226). The median age was 63 yr (IQR 58-68), median GPS was 29 (IQR 21-39), and median PSA was 5.7 ng/ml (IQR 4.6-7.7). In multivariable analyses assessing the odds ratio (OR) per 20-point change in GPS, GPS was an independent predictor of EPE (OR 1.8, 95% confidence interval [CI] 1.4-2.3) and SVI (OR 2.1, 95% CI 1.3-3.4). In addition, when patients were grouped by GPS quartile, the percentage of cases with EPE and SVI increased with the GPS quartile.

Conclusions: We provide evidence that the Oncotype DX GPS is significantly associated with adverse pathology after RP. Specifically, the risk of EPE and SVI increases with the GPS. Therefore, use of the Oncotype DX GPS may help clinicians to improve preoperative patient counseling and develop surgical strategies for patients with a higher chance of EPE or unfavorable pathological features.

Patient summary: We studied whether the score for a prostate genetic test was associated with prostate cancer pathology findings for patients who had their prostate removed. We found that the risk of prostate cancer spread outside the gland and to the seminal vesicle increases with higher test scores. These findings may help surgeons in counseling patients on surgical options for prostate cancer.

Keywords: Genetic testing; Genomic prostate score; Prostate cancer; Robotic radical prostatectomy.