Santos, DanielaGaiteiro, CristianaSantos, MarleneSantos, LúcioDinis-Ribeiro, MárioLima, Luís2023-09-212023-09-212023-07-11Santos, D., Gaiteiro, C., Santos, M., Santos, L., Dinis-Ribeiro, M., & Lima, L. (2023). MicroRNAs Biomarkers for Early Screening of Colorectal Cancer. Proceedings of Research and Practice in Allied and Environmental Health, 1(1), 17. https://doi.org/10.26537/prpaeh.v1i1.5142http://hdl.handle.net/10400.22/23592Colorectal cancer (CRC) is the most incident neoplasia in Portugal. When diagnosed early, the 5-year cancer survival rate increases to 90% [2]. However, the current noninvasive screening method for CRC, Fecal Immunochemical Test (FIT), has low sensitivity and specificity for detecting precancerous lesions. Therefore, it is necessary to develop a new screening method for CRC. MicroRNAs (miRs) play a role in genetic events associated with carcinogenesis, and their disrupted expression in tumors can be readily detected in biological fluids [5-8]. This characteristic offers a promising tool for CRC screening. Review the existing literature to assess the advancements made in recent years in the potential use of miRs as a biomarker to improve the CRC screening. A comprehensive literature review was conducted, analyzing a total of 54 studies that investigated miRs expression in stool and blood samples and evaluated is potential as biomarkers for CRC identification. In our search, we identified a total of 104 miRs with potential relevance to CRC screening in both stool and blood samples. Among these miRs, miR-21-5p and miR-92a-3p, along their cluster including miR-29a-3p, miR-20a-5p, and miR-18-5p, emerged as the most frequently mentioned and promising candidates. Furthermore, is reported a differential expression of miR-135b-5p, miR-223-3p, and miR-451 only in stool specimens, while miR-139-3p and miR-4516 exhibit this altered expression in blood samples. Other notable miRs, including miR-146a-5p, miR-199a-5p, miR-421, miR-27a-3p, and miR-221-3p, have shown promising results in detecting advanced adenomas, exhibiting a better performance compared to FIT. However, these findings require further validation in a larger patient cohort and across different biological samples to confirm their significance for CRC and precancerous lesions detection. Therefore, miRs are regarded as a promising approach for enhancing the detection of CRC, particularly in the identification of precancerous lesions. Nevertheless, further studies are required to assess the accuracy of these molecules as biomarkers.engBiomarkersColorectal cancerEarly screeningMicroRNAsconference object10.26537/prpaeh.v1i1.5142