Comparison of Real-World Outcomes between Patients with BRCA1/2-Positive and Homologous Recombination Repair-Negative Metastatic Castration-Sensitive Prostate Cancer
Advances in Therapy, 2025
Introduction
This real-world study compared time-to-next-treatment (TTNT), time-to-castration resistance (TTCR), and overall survival between patients with BRCA1/2-positive (BRCA+) and homologous recombination repair-negative (HRR-) metastatic castration-sensitive prostate cancer (mCSPC).
Methods
Patients who received a genetic test and initiated treatment for mCSPC (index date) after 1/1/2018 were selected from the Flatiron Health-Foundation Medicine, Inc. Metastatic PC Clinico-Genomic Database (1/1/2017-12/31/2022). Outcomes were compared between patients with ≥ 1 positive BRCA test (BRCA+) and those without detected HRR mutations (HRR-) using weighted Kaplan-Meier analyses and Cox proportional hazards models after baseline characteristics (12 months pre-index) were balanced using inverse-probability of treatment weighting.
Results
In total, 149 patients with BRCA+ and 1066 with HRR- mCSPC were included. Baseline characteristics were well-balanced after weighting. By 24 months after treatment initiation, a significantly higher proportion of the BRCA+ than the HRR- cohort progressed to next treatment [69.7% vs. 56.8%; hazard ratio (HR) = 1.45 (95% confidence interval (CI) 1.10, 1.92), p = 0.009]; median TTNT was shorter in the BRCA+ than the HRR- cohort (10.9 vs. 18.7 months). By 24 months, a significantly higher proportion of the BRCA+ than the HRR- cohort progressed to castration resistance [72.2% vs. 61.4%; HR = 1.46 (95% CI 1.16, 1.84), p = 0.001]; median TTCR was shorter in the BRCA+ than HRR- cohort (12.9 vs. 16.9 months). Numerically fewer patients in the BRCA+ than the HRR- cohort survived 24 months after PC diagnosis [80.6% vs. 85.4%; HR = 1.46 (95% CI 0.99, 2.14), p = 0.054].
Conclusion
Findings demonstrate worse outcomes for patients with BRCA+ mCSPC treated with available advanced therapies, supporting the need for effective genetically targeted therapies in this population.
Authors
Bilen MA, Burbage S, Rossi C, Khilfeh I, Diaz L, Wang Y, Pilon D, Brown G, Shore N, Lowentritt B, Lin DW