Vol. 7, Issue 2, Part A (2025)

Colorectal cancer (CRC) is the third most prevalent cancer diagnosed globally and one of the upmost leading causes of cancer-related mortality. With the advancement of treatment, late cancer diagnosis has been a remarkable barrier to better survival. MicroRNA-21 (miR-21), an oncogenic tumor-associated modulator of pathways, has recently been explored as a candidate biomarker for diagnosing cancer. The present investigation aimed to evaluate the diagnostic value of miR-21 circulating in Iraqi patients with colorectal cancer (CRC). 30 patients with colorectal cancer and a similar number of controls were enrolled; blood samples were drawn for the extraction of RNA using the TRIzol^TM technique. RT-qPCR was performed to analyze miR-21 expression, normalized to U6 as an endogenous control. Results indicated a spectacular elevation of circulating miR-21 in patients with colorectal cancer and a 3.4-fold increase over controls. The expression levels correlated to the stage of disease, from 1.89-fold in stage I to 4.70-fold in stage IIIA. These results re-endorse circulating miR-21 as a candidate non-invasive biomarker for the stratification of colorectal cancer diagnosis as well as progression of disease. The inclusion of miR-21 in screening technologies would enhance early detection and patient outcomes, especially in low-resource settings. Large, multicenter trials are warranted to determine its clinical value.