ASCO 2017: PSA doubling time and proximal PSA value predict metastasis-free survival in men with biochemically recurrent prostate cancer (BRPC) after radical prostatectomy

Chicago, IL ( Dr. Mark Markowski and colleagues from Johns Hopkins University presented their study assessing the implications of PSA doubling time (PSADT) and proximal PSA value for predicting metastasis free survival (MFS) among men with biochemical recurrence after radical prostatectomy (RP) at the prostate cancer poster session at the 2017 ASCO annual meeting. The objective for this study was to identify men with PSADT<12 months and identify a PSA cut-point (proximal PSA) that indicates the imminent emergence of metastasis (M+).

For this study, the authors combined the Center for Prostate Disease Research and Johns Hopkins (CPDR/JHU) databases to investigate the association of the proximal PSA value on MFS in men with biochemical recurrence and PSADT <12 months. Among 31,296 men in the combined cohort, 513 men with BCR (>0.2ng/ml) with PSADT <12 months who received no adjuvant/salvage ADT/RT were prospectively followed until radiological evidence of M+. All patients were evaluated yearly with >1 PSA and scans at regular intervals until M+. The proximal PSA was defined as the most recent value >6 months prior to M+/censor. Among the 513 patients included in the analysis M+ occurred in 218 over a median follow-up of 9 years. The risk of M+ increased successively for PSADT 6.0-7.5, 4.5-6, 3.0-4.5, and <3.0 months, adjusted for pT stage and Gleason score. Proximal PSA ≥10ng/ml significantly increased risk of M+ in patients with PSADT <12 months, regardless of PSADT subgroup (HR 2.95, p<.0001). Median MFS was 4.0 years at proximal PSA >10ng/ml vs 20 years at proximal PSA <10ng/ml. The strength of this study is the long term follow-up with a large number of events and granular variable information, as well as utilizing two unique cohorts of patients.

The authors concluded that in men with PSADT<12 months, PSADT subgroups <7.5 months and proximal PSA >10ng/ml are independent predictors of MFS. Furthermore, a proximal PSA ≥10ng/ml further defines risk of M+ in biochemical recurrence of prostate cancer with PSADT<12 months. With additional validation, this information may provide utility in counselling patients. 

Presented By: Mark C. Markowski, MD, PhD, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Baltimore, MD, USA

Co-Authors: Daniel Suzman, Yongmei Chen, Bruce J. Trock, Jennifer Cullen, Zhaoyong Feng, Emmanuel S. Antonarakis, Channing Judith Paller, Misop Han, Alan W. Partin, Mario A. Eisenberger

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