Serum Neuroendocrine Markers Predict Therapy Outcome of Patients with Metastatic Castration-Resistant Prostate Cancer: A Meta-Analysis

Abstract

Purpose: To evaluate whether serum neuroendocrine markers could effectively predict treatment outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC). Methods: The PubMed, Cochrane Library and Embase databases were sought to identify eligible studies concerning serum neuroendocrine markers and the prognosis of post-treatment mCRPC from inception to April 2018. The association between serum neuroendocrine markers, that is, chromogranin A (CgA) and neurone-specific enolase (NSE), levels and the prognosis of post-treatment mCRPC were summarized using a random-effects model and hazard ratio (HR) with 95% CI Sensitivity analyses were conducted to assess potential bias. Results: A total of 234 participants are included in this meta-analysis (mean age = 71.3 years) from 6 studies. The pooled results show that higher markers’ levels at baseline in patients were associated with unfavorable overall survival (OS; univariate analysis: HR 3.775, 95% CI 1.469–9.698, p = 0.006; multivariate analysis: HR 3.838, 95% CI 1.774–8.304, p = 0.001), and a similar situation was observed in progression-free survival (PFS; univariate analysis: HR 2.785, 95% CI 1.315–5.898, p = 0.007; multivariate analysis: HR 1.266, 95% CI 1.017–1.577, p = 0.035). Estimates of the total effects were generally consistent in the sensitivity analysis. Publication bias was observed when performing the univariate analysis of PFS, and we have the explanation accordingly. Conclusions: The results of this pooled analysis confirm serum neuroendocrine markers could be the effective predictor of treatment outcome in patients with mCRPC. In addition, a combination of CgA and NSE is more valuable to predict worse OS. Further randomized case-control trials are required to validate this relationship.