Cell-Free DNA and Neuromediators in Detecting Aggressive Variant Prostate Cancer

Aggressive variant transformation in metastatic castration-resistant prostate cancer (mCRPC) represents an under-recognized phenomenon. There is an urgent need for non-invasive biomarkers to detect these variants and identify treatment alternatives.

A prospective observational pilot study in mCRPC patients receiving treatment with cabazitaxel (CAB) was conducted. Neuromediators were sequentially evaluated and their impact on disease endpoints calculated. Targeted next-generation sequencing (NGS) of cell-free DNA (cfDNA) was also performed in a highly pretreated subset of patients.

23 patients were included. Estimated effects indicate that neuron-specific enolase (NSE) levels at baseline may be correlated with overall survival (NSE unit 18.3 ng/ml: HR1.262 (95% confidence interval (CI) 0.985-1.616)) and that chromogranin A (CGA) may be correlated with progression-free survival (CGA unit 98.1 ng/ml: HR1.341 (95% CI 1.011-1.778)). cfDNA analysis revealed mutations annotated in prostate cancer (PCA) and small cell cancers (SCC). 1 patient showed elevated neuromediators along with annotated mutations in PCA and SCC, potentially indicating aggressive variant cancer. In 3 patients KIT mutations (e.g. pM541L, pV654A) known to be tissue-based biomarkers with level 1 evidence for the treatment with imatinib and sunitinib were found.

Sequential analysis of neuromediators and targeted NGS of cfDNA provide insight for the estimation of tumor heterogeneity under therapy with CAB.