多种腹部癌症类型的腹膜转移常见且预后不佳。腹膜疾病的存在会提升癌症诊断，并改变许多癌症类型的疾病轨迹和治疗途径。因此，准确及时地检测腹膜疾病至关重要。目前在检测腹膜疾病方面，常见的诊断性腹腔镜和腹腔灌洗细胞学（PLC）具有不同的敏感性。在最初的PLC结果为阴性的患者中，随访期间发现的腹膜复发的显著比例表明了对于检测临床上隐匿的腹膜疾病，尤其是腹膜微转移，需要更好的诊断工具。液体活检的进展使得腹膜肿瘤DNA（ptDNA）的开发和应用成为可能，ptDNA的存在可以作为早期腹膜转移的替代标志物。ptDNA在不同癌症类型的研究文献日益增多，预示着有希望的结果。在这里，我们进行了系统综述，评估了ptDNA在各种癌症类型中的预后影响，并讨论了其潜在的未来临床应用，重点关注胃肠道和妇科恶性肿瘤。©2023. 作者，独家授权给斯普林格自然有限公司。

Peritoneal metastases from various abdominal cancer types are common and carry poor prognosis. The presence of peritoneal disease upstages cancer diagnosis and alters disease trajectory and treatment pathway in many cancer types. Therefore, accurate and timely detection of peritoneal disease is crucial. The current practice of diagnostic laparoscopy and peritoneal lavage cytology (PLC) in detecting peritoneal disease has variable sensitivity. The significant proportion of peritoneal recurrence seen during follow-up in patients where initial PLC was negative indicates the ongoing need for a better diagnostic tool for detecting clinically occult peritoneal disease, especially peritoneal micro-metastases. Advancement in liquid biopsy has allowed the development and use of peritoneal tumour DNA (ptDNA) as a cancer-specific biomarker within the peritoneum, and the presence of ptDNA may be a surrogate marker for early peritoneal metastases. A growing body of literature on ptDNA in different cancer types portends promising results. Here, we conduct a systematic review to evaluate the prognostic impact of ptDNA in various cancer types and discuss its potential future clinical applications, with a focus on gastrointestinal and gynaecological malignancies.© 2023. The Author(s), under exclusive licence to Springer Nature Limited.