Correlation between cribriform/intraductal prostatic adenocarcinoma and percent Gleason pattern 4 to a 22‐gene genomic classifier

Abstract

BackgroundThe Decipher test measures expression of 22 RNA biomarkers associated with aggressive prostate cancer used to improve risk stratification of patients to help guide management. To date, Decipher’s genomic classification has not been extensively correlated with specific histologic growth patterns in prostatic adenocarcinoma. With a growing understanding of the clinical aggressiveness associated with cribriform growth pattern (CF), intraductal carcinoma (IDC), and percent Gleason pattern 4 (G4%), we sought to determine if their presence was associated with an increased genomic risk as measured by the Decipher assay.DesignClinical use of the Decipher assay was performed on the highest Gleason score (GS) tumor nodule of prostatectomy specimens from a prospective cohort of 48 patients, with GS varying from 7 through 9 to help guide clinical risk stratification. The tumors were reviewed for CF, IDC, and G4%, which were then compared to the Decipher score (0‐1) and risk stratification (high vs not high).ResultsThe presence of CF/IDC was significantly associated with Decipher risk score (P = .007), with a high‐risk Decipher score in 22% vs 56% of patients without or with CF/IDC. On binary logistic regression analysis, G4% (odds ratio [OR] 1.04 per percent increase [95% confidence interval [CI], 1.02‐1.06]; P = .0004) and CF predominant (OR, 9.60 [95%CI, 1.48‐62.16]; P = .02) were significantly associated with a high‐risk GC score. IDC did not reach significance (OR, 1.92 [95%CI, 0.65‐5.67]; P = .24).ConclusionsOur findings add to an expanding knowledge base that supports G4% and CF/IDC as molecularly unique and clinically relevant features in prostatic adenocarcinoma. These histologic features should be standardly reported as they are associated with more aggressive prostate cancer. Future work should determine the independent information of these histologic findings that are relative to genomic assessment on long‐term outcomes.