Quick assessment of cell-free DNA in seminal fluid and fragment size for early non-invasive prostate cancer diagnosis

Liquid biopsy consists in the quantification and qualification of circulating cell-free DNA (cfDNA) and tumor-derived DNA (ctDNA) for cancer recognition. Recently, the characterization of seminal cfDNA (scfDNA) has been reported as a possible biomarker for prostate cancer (PCa) diagnosis. Thirty patients with histologically proven PCa, 33 with benign prostate hyperplasia (BPH) and 21 healthy controls were enrolled. cfDNA was extracted from seminal fluid samples. cfDNA quantification and analysis were performed using Qubit ssDNA Kit and Agilent 2100 Bioanalyzer. Statistical analysis included: Levene's test, Shapiro-Wilk, Kolmogorov-Smirnov and Kruskal Wallis tests. Median cfDNA was significantly higher in PCa patients 428.45 ng/mL (173.93–1159.62) compared to BPH patients 77.4 ng/mL (18.23–501) and healthy controls 25.4 ng/mL (15.37–76.62). scfDNA fragments longer than 1000 base-pairs were more common in patients with PCa compared to those with BPH and controls. scfDNA concentration and fragment size differed significantly in the three groups of PCa, BPH and healthy controls. Both parameters are potential clinical biomarkers for PCa and can be used in both early diagnosis and follow-up. Using automated systems for high-throughput cfDNA quantification could improve the reproducibility of the method and facilitate the implementation of liquid biopsies in the clinical setting. •Liquid biopsy consists in the quantification and qualification of circulating cell-free DNA and tumor-derived DNA.•The characterization of seminal cfDNA (scfDNA) is a potential biomarker for prostate cancer diagnosis.•Median cfDNA from PCa patients were significantly higher than those from BPH patients and healthy controls.•A higher concentration of long scfDNA fragments was observed in PCa patients in respect to BPH patients and healthy controls tumor•scfDNA can be adopted in early diagnosis of PCa and clinical surveillance, avoiding unnecessary biopsies.•Automated systems for cfDNA analysis could facilitate the implementation of liquid biopsy in the uro-oncological setting.