Clinical Outcomes of Neuroendocrine Prostate Cancer Treated With Platinum-Based Chemotherapy: A Single-Institution Experience.

INTRODUCTION Neuroendocrine prostate cancer (NEPC) is aggressive with a poor prognosis. Most reported series derive from large databases (e.g., SEER) lacking granular clinical detail. We examined our institution's experience with 58 patients with NEPC. PATIENTS We identified patients with biopsy-proven NEPC treated with platinum-based chemotherapy. De novo versus treatment-emergent (t-NEPC) status, stage, and treatment history were recorded.

Methods

For localized NEPC treated with definitive intent, disease-free survival (DFS) was measured from NEPC diagnosis to relapse or death; for metastatic NEPC, systemic therapies were noted. Overall survival (OS) was defined as time from NEPC diagnosis to death and estimated by Kaplan-Meier method, with log-rank comparisons.

Results

Fifty-eight patients with NEPC were identified (median age, 66 years); 19 (32.8%) had de novo NEPC and the remainder had t-NEPC. Forty-four (75.9%) had metastatic disease at NEPC diagnosis. Histology was pure small cell (n = 15), neuroendocrine (n = 21), or mixed (n = 22, e.g., with adenocarcinoma). Of 14 patients without metastases at diagnosis, 10 received definitive local therapy (median DFS, 11.7 months). OS was longer for de novo versus t-NEPC disease (26.5 vs 10.9 months, P = 0.0001) and for mixed versus pure histology (21.0 vs 11.0 months, P = 0.0002). Among 45 patients with metastatic NEPC treated with first-line carboplatin and etoposide, OS did not differ with versus without maintenance immunotherapy (12.5 vs 11.0 months, P = 0.9).

Conclusion

In one of the largest non-database series of patients with NEPC, OS was longer for de novo disease and mixed histology. Maintenance IO after carboplatin plus etoposide was not associated with improved OS.