The invention belongs to the technical field of biological medicines, and particularly relates to an application of a CD11b positive
exosome in tumor prognosis evaluation. According to the invention,
peripheral blood samples of healthy people,
colorectal cancer patients and patients before and after an operation are collected,
human plasma CD11b + exosomes and CD11b-exosomes are sorted by adopting
flow cytometry, and the content of S100A9 in the CD11b + exosomes is detected by utilizing ELISA. The S100A9
protein in the
plasma CD11b + exosomes is determined to have a significant high expression quantity, and has sensitivity and specificity for judging recurrence and
metastasis of a
colorectal cancer; and meanwhile, the application has the characteristics of simple operation, sensitive detection, good specificity, high
repeatability and the like. The application confirms that the expression level of the S100A9
protein in CD11b + exosomes is related to the prognosis of the postoperative
colorectal cancer patient, can be used for judging the prognosis of the colorectal
cancer patient, and has important guiding significance for reducing the death rate of the colorectal
cancer and improving the prognosis.