ASCO 2023: Assessing PSA Levels as Prognostic of Overall Survival in Men with mHSPC

(UroToday.com) The 2023 ASCO annual meeting included a prostate cancer session, featuring a presentation by Dr. Susan Halabi discussing the assessment of PSA levels as a prognostic factor for overall survival in men with metastatic hormone-sensitive prostate cancer (mHSPC). Prior data have shown that PSA ≤ 0.2 ng/dL at 6-7 months with ADT with testosterone suppression alone is prognostic of OS. Dr. Halabi and colleagues hypothesized that a PSA ≤0.1 ng/dL at 7 months would be a stronger prognostic factor for OS in men with mHSPC treated with testosterone suppression alone. This hypothesis was investigated by the STOPCAP M1 collaborators.


Individual patient data from 13 eligible randomized trials comparing treatment regimens (testosterone suppression or testosterone suppression + docetaxel in the control or research arms in mHSPC trials) were utilized. Landmark survival analyses were performed at 7 months after ADT initiation. Overall survival was computed as the time from 7 months after start of initial testosterone suppression to death or date of last follow for patients who started testosterone suppression prior to randomization or 7 months after randomization to death or date last follow-up for patients who started testosterone suppression after randomization. PSA measurements between 4-7 months after ADT were selected and cut off-points of PSA ≤0.2, 0.2-4, and >4 ng/dL or PSA ≤0.1, 0.1-0.2, 0.2-4, and >4 ng/dL were considered. The proportional hazards model was utilized to explore the prognostic significance of PSA levels in predicting OS adjusting for treatment in all patients and patients who were enrolled on docetaxel trials.

 Individual patient data from 5,438 patients randomized 1994-2012 from 13 trials were pooled. At 4-7 months, the proportion of patients who had PSA≤0.1 and PSA ≤0.2 were 18.1% and 26.1%, respectively. The OS Kaplan-Meier plots by PSA levels are as follows: 

STOPCAP M1.jpg

The median OS in patients who experienced PSA ≤0.1 and PSA ≤0.2 and in patients enrolled on docetaxel trials are presented in the following table:

STOPCAP M1 ASCO.jpg

The hazard ratios for death for PSA ≤0.1 and PSA ≤0.2 vs. those PSA >4 at 4-7 months were 0.26 and 0.27, respectively. In patients enrolled on docetaxel, HRs for death for PSA ≤0.1 and PSA ≤0.2 vs. those PSA >4 at 7 months were 0.35 and 0.34, respectively.

Dr. Halabi concluded her presentation discussing the assessment of PSA levels as a prognostic factor for overall survival in men with mHSPC with the following take-home points:

  • PSA ≤0.1 and PSA ≤0.2 at 7 months have similar prognostic value of OS in men with mHSPC treated with weak ADT (testosterone suppression alone) without and with docetaxel

Presented by: Susan Halabi, PhD, Duke University Medical Center, Durham, NC

Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting, Chicago, IL, Fri, June 2 – Tues, June 6, 2023.