微小RNA(microRNA,miRNA)在恶性肿瘤中异常表达,与肿瘤的发生和发展密切相关。上皮细胞恶性肿瘤中miRNAs可通过脱落的肿瘤细胞随排泄物排出体外,因此检测排泄物(粪便、痰和尿)中的肿瘤特异性miRNAs可能成为消化系统、肺和膀胱恶性肿瘤早期诊断的新的生物学标志物。本文就miRNAs与肿瘤发生和发展的关系以及排泄物miRNAs检测在消化系统肿瘤、膀胱癌和肺癌早期诊断中的研究进展进行简要综述。 MicroRNAs (miRNAs) are abnormally expressed in malignant tumors and are closely related to the occurrence and development of tumors. MiRNAs in epithelial malignancies can be excreted with excreted tumor cells by exfoliated cells. Therefore, detection of tumor-specific miRNAs in excreta (faeces, sputum and urine) may become a new diagnostic tool for digestive system, early diagnosis of lung and bladder malignancy Biological markers. This review summarizes the progress of miRNAs in tumorigenesis and progression and the progress of detection of excretion miRNAs in the early diagnosis of digestive system tumors, bladder cancer and lung cancer.