Prostate cancer (PC) remains a leading cause of malignancy in men worldwide, with current diagnostic methods such as prostate-specific antigen (PSA) testing and tissue biopsies facing limitations in specificity, invasiveness, and ability to capture tumor heterogeneity. Liquid biopsy, especially analysis of circulating tumor DNA (ctDNA), has emerged as a transformative tool for non-invasive detection, real-time monitoring, and treatment selection for PC. This review examines the role of ctDNA in both localized and metastatic PCs, focusing on its utility in early detection, risk stratification, therapy selection, and post-treatment monitoring. In localized PC, ctDNA-based biomarkers, including ctDNA fraction, methylation patterns, fragmentation profiles, and mutations, demonstrate promise in improving diagnostic accuracy and predicting disease recurrence. For metastatic PC, ctDNA analysis provides insights into tumor burden, genomic alterations, and resistance mechanisms, enabling immediate assessment of treatment response and guiding therapeutic decisions. Despite challenges such as the low ctDNA abundance in early-stage disease and the need for standardized protocols, advances in sequencing technologies and multimodal approaches enhance the clinical applicability of ctDNA. Integrating ctDNA with imaging and traditional biomarkers offers a pathway to precision oncology, ultimately improving outcomes. This review underscores the potential of ctDNA to redefine PC management while addressing current limitations and future directions for research and clinical implementation.
前列腺癌（PC）仍是全球男性恶性肿瘤的主要病因之一，当前基于前列腺特异性抗原（PSA）检测和组织活检的诊断方法在特异性、侵入性及捕捉肿瘤异质性方面存在局限。液体活检技术，尤其是循环肿瘤DNA（ctDNA）分析，已成为前列腺癌无创检测、实时监测和治疗选择的重要变革性工具。本文综述了ctDNA在局限性与转移性前列腺癌中的作用，重点关注其在早期检测、风险分层、治疗方案选择及治疗后监测中的应用价值。在局限性前列腺癌中，基于ctDNA的生物标志物（包括ctDNA含量、甲基化模式、片段化特征及基因突变）展现出提升诊断准确性和预测疾病复发的潜力。对于转移性前列腺癌，ctDNA分析可揭示肿瘤负荷、基因组改变及耐药机制，实现对治疗反应的即时评估并指导临床决策。尽管早期疾病中ctDNA丰度较低及标准化检测方案尚待完善等挑战依然存在，但测序技术的进步与多模态整合策略正不断提升ctDNA的临床适用性。将ctDNA与影像学及传统生物标志物相结合，为精准肿瘤治疗提供了可行路径，最终有望改善患者预后。本综述系统阐述了ctDNA重塑前列腺癌诊疗体系的潜力，同时探讨了当前局限性与未来研究及临床转化的方向。
肿瘤(癌症)患者之家