ASCO 2017: The ABC-study: A randomized phase III study comparing one course of adjuvant bleomycin, etoposide, and cisplatin (BEP) and one course of carboplatin AUC7 in clinical stage I seminomatous testicular cancer

Chicago, IL ( Dr. Tandstad and colleagues presented their study design of the ABC study, a randomized phase III study comparing one course of adjuvant bleomycin, etoposide, and cisplatin (BEP) and one course of carboplatin among patients with stage I seminoma testicular cancer, at today’s ASCO 2017 annual meeting. Treatment options for stage I seminoma include surveillance or adjuvant treatment. The authors note that tumor size and stromal invasion in the rete testis can be used to identify patients with a higher risk of relapse, and that previous studies have only shown a modest effect of adjuvant carboplatin in preventing relapse. The hypothesis is that BEP will improve time to recurrence compared to standard carboplatin.

For this study, the authors note that based on the SWENOTECA data from one course of adjuvant carboplatin AUC7 [1], the estimated relapse rate in patients with one or two risk factors is 9%. Following orchiectomy and confirmation of stage I seminoma, patients will be randomized 1:1 to carboplatin vs BEP. The primary outcome will be relapse-free survival (RFS). The authors consider a reduction in RFS of 7% to be the minimum difference that will lead to routine use of one course of adjuvant BEP. To demonstrate an improvement in relapse rate from 9% to 2% with an α of 0.05 and β of 0.80, the study will require 332 evaluable patients.

Enrollment for this study started in 2015, and as of May 19, 2017, 84 patients have been enrolled at a rate of 5-6 patients per month. Although the investigators feel accrual has been slower than anticipated, the momentum is increasing and they are inviting investigators and collaborative groups to participate in the study.

Presented By: Parminder Singh, Mayo Clinic Arizona, Phoenix, AZ, USA

Co-Authors: Tangen Catherine, Seth P. Lerner, David McConkey, Melissa Plets, M. Scott Lucia, Michael Woods, Trinity Bivalacqua, Wassim Kassouf, Richard Carlton Bangs, Ian Murchie Thompson, Peter C. Black

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 – Chicago, Illinois, USA

Tandstad T, Stahl O, Dahl O, et al. Treatment of stage I seminoma, with one course of adjuvant carboplatin or surveillance, risk-adapted recommendations implementing patient autonomy: A report from the Swedish and Norwegian Testicular Cancer Group (SWENOTECA). Ann Oncol 2016 Jul;27(7):1299-1304.