Abstract:Objective To analyze the levels of serum microRNA（miR）-212-5p and miR-576-5p in colorectal cancer（CRC）patients and their clinical value in prognosis. Methods A total of 117 CRC patients（observation group） admitted to First Hospital of Qinhuangdao from April 2019 to April 2021 and 50 healthy volunteers（control group） were enrolled as subjects. Postoperative follow-up was conducted for 3 years to record the survival outcomes of the patients. According to the survival status at the end of the follow-up, the patients with colorectal cancer were divided into survival group（n=91）and death group（n=26）. The real-time fluorescence quantitative PCR（qRT-PCR）was used to measure the expression levels of serum miR-212-5p and miR-576-5p in each group. Pearson's correlation test was employed to analyze the correlation between the expression levels of serum miR-212-5p and miR-576-5p in CRC patients. The relationship between serum miR-212-5p，miR-576-5p levels and the clinicopathological characteristics of the patients was examined. Receiver operating characteristic (ROC) curve analysis was used to evaluate the early diagnosis value and prognostic predictive efficacy of serum miR-212-5p and miR-576-5p in colorectal cancer. Results Compared with the control group，the expression level of serum miR-212-5p in the observation group was decreased，while the expression level of miR-576-5p was increased（P<0.05）. Compared with the survival group，the death group exhibited lower serum miR- 212-5p expression and higher miR-576-5p expression（P<0.05）. Serum miR-212-5p and miR-576-5p levels in CRC patients showed a significant negative correlation（ r=-0.598，P<0.05）. The serum levels of miR-212-5p and miR-576-5p in CRC patients were closely associated with TNM stage and lymph node metastasis（P<0.05）. The area under the curve（AUC）for serum miR-212-5p and miR-576-5p individually and in combination for diagnosing CRC were 0.764，0.827，and 0.907，respectively，with the combined detection outperforming each individual detection（Z_{combination-miR-212-5p}=3.902，Z_{combination-miR-576-5p}=3.170，P<0.05）. The AUC for predicting CRC patient mortality using serum miR-212-5p and miR-576-5p individually and in combination were 0.861，0.720，and 0.937， respectively，with the combined detection outperforming each individual detection（Z_{combination-miR-212-5p}=2.460，Z_{combination-miR-576-5p}=4.377，P<0.05）. Conclusion Serum miR-212-5p expression is reduced and miR-576-5p expression is increased in CRC patients. The combination of these two can provide clinical evidence for early diagnosis and prognosis of CRC.