Evaluating cell-free DNA genetic alterations in men with metastatic castrate resistant prostate cancer.

244 Background: Personalizing CRPC therapy is desirable but difficult as biomarkers that have predictive value other than AR-V7 are scarce. Novel biomarkers that can be repetitively assessed via non-invasive methods may provide important insights into disease biology and therapeutic selection. Cell free DNA (cfDNA) is found in the blood of advanced cancer patients and potentially reflects tumor-related genetic alterations. Herein, we evaluated plasma cfDNA genetic alterations in men with CRPC. Methods: We isolated cfDNA from the plasma of 11 men with metastatic CRPC. Following library prep, paired-end sequencing was performed using Illumina Hi-Seq 2000. A bioinformatics pipeline was used for data pre-possessing including alignment, duplicate removal, normalization and variant calling. Visualization and statistical analyses were performed with SNP & Variation Suite v8.x. Additional analyses will follow on translocations. Results: Preliminary analysis of cfDNA showed stopgain mutations in CDC27, FAM104B and...