Risk of Biochemical Recurrence in Patients with Grade Group 1 Prostate Cancer with Extraprostatic Extension Treated with Radical Prostatectomy

To examine the association of extraprostatic extension (EPE) with biochemical recurrence (BCR) separately in men with grade group 1 (GG1) and GG2 prostate cancer (PCa) treated with radical prostatectomy.We reviewed our institutional database of patients who underwent radical prostatectomy for PCa between 2005 and 2022 and identified patients with GG1 and GG2 disease on final pathology. Fine-Gray competing risk models with an interaction between EPE (yes vs no) and grade group (GG1 vs GG2) were used to examine the relationship between disease group and BCR-free survival.The cohort consisted of 6309 men, of whom 169/2740 (6.2%) with GG1 disease had EPE while 1013/3569 (28.4%) with GG2 disease had EPE. Median follow up was 4 years. BCR occurred in 400/6309 (6.3%) patients. For men with GG1, there was no statistically significant difference in BCR-free survival for men with vs without EPE (subdistribution hazard ratio [SHR] = 0.88; 95% CI: 0.37-2.09). However, for GG2 patients BCR-free survival was significantly worse for those with vs without EPE (SHR = 1.97, 95% CI: 1.54-2.52).Although there are a subset of GG1 PCa's capable of invading through the prostatic capsule, patients with GG1 PCa and EPE at prostatectomy experience similar biochemical recurrence and survival outcomes compared to GG1 patients without EPE. However, among men with GG2 EPE connotes a worse prognosis.