Incidence of EMBARK and EAU high-risk biochemical recurrence and prostate cancer mortality: A real-life population-based study.

Abstract

372 Background: The EMBARK trial proved the efficacy of enzalutamide plus leuprolide in patients with prostate cancer (PCa) who have had high-risk biochemical recurrence (BCR). Different criteria are currently used to define high-risk BCR. The aim of this study was to evaluate the incidence of several definitions of High-risk BCR after radical prostatectomy (RP) or radiotherapy (RT) and their association with PCa specific mortality (PCSM). Methods: Population-based study including 17,753 men undergoing RP (n=12,010) or RT (n=5743) with curative intent (cT1-3, cM0) and PSA follow-up in Stockholm between 2003 and 2021. Follow-up for all patients was until death, emigration, or end of the study period (December 31, 2021). Primary outcomes were the cumulative incidence of any BCR (RP: PSA≥ 0.2; RT: PSA≥ nadir+2) and high-risk BCR (according to EAU and Embark criteria) estimated using the Kaplan Mayer method and PCSM accounting for competing risk. Results: The 10-year cumulative incidences of any BCR, EAU, and Embark high-risk BCR were 25% (95% CI 24, 26), 10% (9, 11), 4% (3, 4) after RP and 20% (19, 22), 10% (9, 11) and 10% (9, 11) after RT. Median time from RP to high-risk BCR was 12.6 (5.8, 25.7) months for EAU criteria and 11.8 (5.1, 22.3) months for Embark criteria. Similarly median time from RT to high-risk BCR was 21.2 (11.3, 45.9) months for EAU criteria and 23.4 (14.3, 38.3) months for Embark criteria.After RP, the 10-year Cumulative incidences of PCSM were 11% (95% CI: 9, 13), 17% (14, 21) and 30% (24, 37) for any BCR, EAU and Embark high-risk BCR, respectively. After RT, the 10-year PCSM cumulative incidences were 39% (35, 44), 50% (45, 56) and 49% (42, 55), respectively. Conclusions: Incidence of High-Risk BCR vary according to the definition used and primary treatment. High risk BCR usually happen early after treatment and most patients with any PSA elevation will never experience High-risk BCR during the follow-up. Embark criteria currently represent the more stringent criteria with a very high risk of PCSM. Pattern of presentations of BCR, and high-risk BCR according to EAU and EMBARK criteria after radical prostatectomy or radiotherapy. Primary treatment Radical Prostatectomy Radiotherapy PSA> 0.2 N=2501 EAU High Risk BCR N=1119 EMBARK High Risk BCR N=386 PSA>Nadir + 2 N=836 EAU High Risk BCR N=427 EMBARK High Risk BCR N=456 Time frame, n (%) 0-1 year 660 (26.4%) 535 (47.8%) 199 (51.6%) 117 (14.0%) 117 (27.4%) 96 (21.1%) 1-3 years 757 (30.3%) 392 (35.0%) 139 (36.0%) 297 (35.5%) 171 (40.0%) 229 (50.2%) 3-5 years 463 (18.5%) 111 (9.9%) 29 (7.5%) 198 (23.7%) 79 (18.5%) 109 (23.9%) 5-7 years 286 (11.4%) 48 (4.3%) 10 (2.6%) 85 (10.2%) 23 (5.4%) 16 (3.5%) >7 years 335 (13.4%) 33 (2.9%) 9 (2.3%) 139 (16.6%) 37 (8.7%) 6 (1.3%) Time to BCR, n (%) 29.7 (11.3, 59.6) 12.6 (5.8, 25.7) 11.8 (5.1, 22.3) 36.6 (18.6, 62.4) 21.2 (11.3, 45.9) 23.4 (14.3, 38.3)