(UroToday.com) The 2026 American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting, held in Chicago, IL, will host the Prostate, Testicular, and Penile Cancer – Posters Session. Dr. Georges Gebrael will present Abstract 5096: Correlation of baseline testosterone level with survival outcomes in patients with mHSPC: Analysis of patient-level data from SWOG 1216 study.
Dr. Gebrael highlighted that retrospective studies have previously suggested an association between low baseline testosterone levels and inferior outcomes in metastatic hormone-sensitive prostate cancer (mHSPC), although prospective validation within randomized clinical trial populations has remained limited. Using patient-level data from the phase 3 SWOG 1216 trial, the investigators evaluated the prognostic significance of baseline testosterone levels in patients treated with ADT plus either bicalutamide or orteronel.1
This secondary analysis included 218 patients from SWOG 1216 with available baseline testosterone measurements. Median baseline testosterone level was 312.5 ng/mL (IQR 89.25–462 ng/mL). Patients were dichotomized according to testosterone levels above or below the median, with overall survival (OS) serving as the primary endpoint and progression-free survival (PFS) and PSA response as secondary endpoints.
Dr. Gebrael noted that no statistically significant differences in outcomes were observed according to baseline testosterone levels in either treatment arm. Within the experimental arm (ADT + orteronel), median OS was 63 months (95% CI 47–NR) among patients with testosterone levels ≤ median compared with not reached (95% CI 68–NR) for patients with testosterone levels > median (p=0.11). Median PFS was 30 months (95% CI 20–64) versus 57 months (95% CI 26–NR), respectively (p=0.11).
Similarly, within the standard arm (ADT + bicalutamide), median OS was 72 months (95% CI 45–NR) for patients with testosterone levels ≤ median compared with 57 months (95% CI 43–NR) among those > median (p=0.7). Median PFS was 19 months in both groups, with no statistically significant differences observed (p=0.9).
No differences in PSA response rates at the 7-month landmark were observed between testosterone groups in either treatment arm. In the experimental arm, PSA complete response rates were 50% in both groups, while no PSA response was observed in 62% versus 38% of patients with testosterone levels ≤ versus > median, respectively (p=0.5). In the standard arm, PSA complete response rates were 42% versus 58%, respectively, with no significant differences in PSA response categories (p>0.9).
Dr. Gebrael further noted that additional analyses using testosterone quartiles and continuous testosterone values similarly failed to demonstrate significant associations with clinical outcomes.
Dr. Gebrael concluded his presentation with the following key messages:
- Baseline testosterone levels were not significantly associated with OS, PFS, or PSA response in patients with mHSPC treated on the SWOG 1216 trial (1)
- Findings were consistent across both the experimental and standard treatment arms
- Additional analyses using testosterone quartiles and continuous testosterone measurements similarly failed to identify prognostic significance
- These data suggest that baseline testosterone may not be useful for prognostication or treatment selection in patients receiving systemic therapy for mHSPC
- The relatively small sample size remains an important limitation, and external validation is warranted
Presented by: Georges Gebrael, MD, Resident Physician, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
Written by: Julian Chavarriaga, MD, Clinical Assistant Professor, Urologic Oncologist, Department of Urology at Penn State Health @chavarriagaj on X during the American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting held in Chicago, IL between May 29th and June 1st, 2026
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