DNA-repair status should be assessed in treatment-emergent neuroendocrine prostate cancer before platinum-based therapy.

Abstract

Objectives: This study sought to provide contemporary data from a multi-institution with respect to DNA-repair genes (DRGs) status and its impact on effects of platinum-based chemotherapy in treatment-emergent neuroendocrine prostate cancer (t-NEPC), for which little data exist.

Patients and methods: All patients were retrospectively collected with eligible biopsied tissues for targeted next generation sequencing (NGS). The main outcomes were radiologic progression-free survival and overall survival according to Response Evaluation Criteria in Solid Tumors, version 1.1.

Results: Among the 43 NEPC patients, 13/43 (30%) harbored homozygous deletions, deleterious mutations, or both in DRGs. Eleven patients (11/13, 85%) with DRGs aberrations had effective response, including 7 patients with BRCA1/2 defects and 2 with mismatch repair-deficient caused by MSH2 alterations. While significantly fewer responders (30%) were detected in patients without DRGs aberrations (odds ratio = 12.83, p = 0.003). Compared with patients without genomic DRGs aberrations, the hazard ratio (HR) for radiologic progression in those with DRGs defects was 0.42 (95% confidence interval [CI]: 0.19-0.93), and the HR for death was 0.65 (95% CI: 0.24-1.72). The most common adverse event of Grade 3 or 4 was anemia, as noted in 7 patients (16%).

Conclusion: The DRGs status is therapeutically meaningful in t-NEPC. Given the potential responses to platinum-based chemotherapy, our findings support the clinical use of NGS in t-NEPC patients to identify DRGs aberrations.