Abstract: In one aspect, the present disclosure relates to a panel of biomarkers, a kit for detecting it, and its use in the detection of microsatellite instability (MSI) as well as non-invasive diagnosis, prognostic evaluation, selection of treatment or genetic screening of cancer, preferably colorectal cancer (such as bowel cancer), gastric cancer or endometrial cancer in a plasma sample. On the other hand, the present disclosure provides a method for detecting microsatellite instability (MSI) and disease-related gene mutations through plasma based on next-generation sequencing, and a device for implementing the method, especially the use of such detection method in the non-invasive diagnosis, prognostic evaluation, selection of treatment or genetic screening of patients with cancer, preferably colorectal cancer (such as bowel cancer), gastric cancer or endometrial cancer.