EAU 2021: Impact of Prior Local Therapy on Survival in mCRPC: Results from COU-AA-302 Trial

(UroToday.com) At the metastatic prostate cancer session at the European Association of Urology 2021 annual meeting, Dr. Miguel Aliaga discussed the impact of prior local therapy on survival in metastatic castration-resistant prostate cancer (mCRPC). The role of prior local therapy on the outcomes of men with metastatic prostate cancer is a subject of growing interest. Retrospective studies have suggested an improved survival in metastatic hormone-sensitive prostate cancer (mHSPC) patients who underwent prior local therapy with radical prostatectomy or radiation therapy. The effect of prior local therapy in newly diagnosed mCRPC patients and its prognostic significance remains unknown. The objective of this study was to evaluate the incidence and prognostic significance of prior local therapy with radical prostatectomy or radiotherapy on overall survival (OS) in chemo-naïve mCRPC patients treated with abiraterone acetate/placebo + prednisone.

This study was a retrospective analysis of chemotherapy-naïve mCRPC patients from the COU-AA-302 trial1. Patients were categorized based on prior local therapy (radical prostatectomy or radiotherapy). Kaplan-Meier method was used to estimate OS, biochemical progression-free survival, and radiographic progression-free survival. Cox proportional hazards regression model was used to test the association of prior local therapy with OS, biochemical progression-free survival, and radiographic progression-free survival.

Of 1,088 patients included in the study, 469 (43.1%) were M0, 277 (25.5%) were M1, and 337 (31%) were metastasis at diagnosis. The Median time from prostate cancer diagnosis to randomization was 80 months for M0 patients and 28 months for M1 patients. There were 408 (87%) M0 patients that underwent prior local therapy, including 196 (41.8%) that had prostatectomy and 323 (68.9%) that underwent radiotherapy. Prior local therapy was associated with a significant benefit in OS (33.5 versus 25.4 months; HR: 0.61; p=0.001):

 

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and a radiographic progression-free survival benefit (11.7 versus 8.3 months; HR: 0.71; p=0.015):

EAU21_Aliaga_Figure2.jpg 

 

There was no biochemical progression-free survival benefit observed. Radical prostatectomy but not radiotherapy (HR 0.91; p=0.404) was associated with improved OS:

 

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The improvement in OS based on prior local therapy (HR 0.66, 95% CI 0.47-0.94) was maintained in a multivariable prognostic model.

Dr. Aliaga concluded his presentation with the following take-home messages:

  • Men with metastatic castration-resistant prostate cancer who underwent prior local therapy had improved OS when compared to men with no prior local therapy
  • This survival benefit is consistent with previous reports on the hormone-sensitive setting 

Presented By: Miguel Rodrigo Aliaga, Hospital General Universitario, Dept. of Urology, Castellon, Spain

Co-Authors: Lorente Estellés D.2, Garau Perelló C.1, Sánchez Llopis A.1, Bosquet Sanz M.1, Di Capua Sacoto C.3, Villamón Fort R.3, Blasco Maspons J.A.4, Alonso Coscojuela M.4, Sánchez Hernández A.2

1Hospital General Universitario, Dept. of Urology, Castellon, Spain, 2Hospital Provincial, Dept. of Urology, Castellon, Spain, 3Hospital La Plana, Dept. of Urology, Vila-real, Spain, 4Hospital Comarcal Vinaroz, Dept. of Urology, Vinaroz, Spain

Written By: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2021 European Association of Urology, EAU 2021- Virtual Meeting, July 8-12, 2021.

References:

  1. Ryan CJ, Smith MR, de Bono JS, et al. Abiraterone in metastatic prostate cancer without previous chemotherapy. N Engl J Med. 2013;368(2):138-148.