Serum MicroRNA-21 as a Biomarker for Colorectal Cancer Diagnosis

Abstract

Colorectal cancer (CRC), a leading malignancy globally, is increasingly prevalent in low- and middle-income countries due to urbanization and lifestyle changes. In Egypt, CRC ranks as the 7th most common cancer, with most cases progressing over decades through adenoma–carcinoma sequences or serrated pathways. Early detection is crucial, as CRC is preventable and treatable in its early stages, but current diagnostic methods like colonoscopy are invasive, costly, and operator-dependent. Non-invasive biomarker tests, including carcinoembryonic antigen (CEA) and CA 19-9, have shown utility in monitoring CRC but lack optimal sensitivity and specificity. MicroRNA-21, a small non-coding RNA involved in gene regulation, is frequently overexpressed in CRC and has been linked to tumor proliferation, invasion, and metastasis. This study aimed to evaluate serum microRNA-21 levels as a diagnostic biomarker for CRC. Conducted at Qena University Hospital, Egypt, the cross-sectional study included 50 CRC patients and 50 healthy controls. Serum microRNA-21 levels were analyzed using RT-PCR and the 2-ΔΔCt method, excluding individuals with confounding factors such as prior cancer treatments or elevated CEA and CA 19-9 levels. The findings are expected to underscore microRNA-21’s potential as a non-invasive diagnostic tool for CRC, offering high sensitivity and specificity. This could aid in reducing the reliance on invasive diagnostic techniques and improving early detection, ultimately lowering CRC-associated mortality.