Although prostate cancer (PCa) is one of the most common tumors in European males, the only minimally invasive diagnostic tool in PCa setup is the determination of PSA in serum. Cell-free DNA (cfDNA) has been demonstrated to be helpful for PCa diagnosis but has not yet been integrated into the clinical setting. This review aims to provide a systematic update of cfDNA and its fragmentation patterns in PCa reported in literature published over the last twenty years. Due to the high variability of the scientific methods adopted and a lack of standardized median cfDNA levels, results fluctuate across different studies. These differences may be due to the cfDNA source, the quantification method, or the fragmentation pattern. Blood plasma is the most frequently analyzed biological fluid, but seminal plasma has been reported to contain higher cfDNA concentration due to its vicinity to the tumor origin. CfDNA has been shown to be composed of single-stranded (ssDNA) and double-stranded DNA (dsDNA), so the total cfDNA concentration should be preferred as it corresponds best to the tumor mass. Fluorometry and capillary electrophoresis (CE) may be quick and cost-effective tools for cfDNA assessment in a clinical setting. The greatest future challenge is the elaboration of common guidelines and standardized procedures for diagnostic laboratories performing cfDNA analysis. A multiparametric approach combining the analysis of total cfDNA (both ssDNA and dsDNA), cfDNA fragment length, and specific genetic mutations (ctDNA assessment) is required for optimal future applications of liquid biopsy.

尽管前列腺癌（PCa）是欧洲男性中最常见的肿瘤之一，但PCa设置中唯一的微创诊断工具是测定血清PSA。无细胞DNA（cfDNA）已被证明有助于PCa诊断，但尚未整合到临床中。这篇综述旨在提供过去二十年来发表的文献中报道的PCa中cfDNA及其片段化模式的系统更新。由于所采用的科学方法的高度可变性以及缺乏标准化的cfDNA中位数水平，结果在不同的研究中会有所波动。这些差异可能是由于cfDNA来源，定量方法或片段化模式引起的。血浆是分析最频繁的生物液体，但是据报道，精浆由于其靠近肿瘤起源而含有较高的cfDNA浓度。已显示CfDNA由单链（ssDNA）和双链DNA（dsDNA）组成，因此应首选总cfDNA浓度，因为它最适合肿瘤块。荧光法和毛细管电泳（CE）在临床环境中可能是用于cfDNA评估的快速且经济高效的工具。未来最大的挑战是为执行cfDNA分析的诊断实验室制定通用指南和标准化程序。对于液体活检的最佳未来应用，需要将总cfDNA（ssDNA和dsDNA两者），cfDNA片段长度和特定基因突变（ctDNA评估）相结合的多参数方法。