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Updated: Apr 23, 2026

Detection of a Circulating MicroRNA Custom Panel in Patients with Metastatic Colorectal Cancer
Published on: March 14, 2019
microRNA-221 and microRNA-18a identification in stool as potential biomarkers for the non-invasive diagnosis of
11] Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China [2] Gastrointestinal Cancer Biology & Therapeutics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
Background:
The detection of microRNA (miRNA) dysregulation in stool is a novel approach for the diagnosis of colorectal carcinoma (CRC). The aim of this study is to investigate the use of miR-221 and miR-18a in stool samples as non-invasive biomarkers for CRC diagnosis.
Methods:
A miRNA expression array containing 667 miRNAs was performed to identify miRNA dysregulation in CRC tissues. We focused on miR-221 and miR-18a, two significantly upregulated miRNAs which were subsequently verified in 40 pairs of CRC tissues and 595 stool samples (198 CRCs, 199 polyps and 198 normal controls).
Results:
miR-221 and miR-18a were upregulated in the miRNA expression array. miR-221 and miR-18a levels were also significantly higher in 40 CRC tumours compared with their respective adjacent normal tissues. In stool samples, miR-221 and miR-18a showed a significant increasing trend from normal controls to late stages of CRC (P<0.0001). The levels of stool miR-221 and miR-18a were both significantly higher in subjects with stages I+II (miR-221: P<0.0001, miR-18a: P<0.0001) and stages III+IV of CRC (miR-221: P=0.0004, miR-18a: P<0.0001) compared with normal controls. The AUC of stool miR-221 and miR-18a were 0.73 and 0.67 for CRC patients as compared with normal controls, respectively. No significant differences in stool miR-221 and miR-18a levels were found between patients with proximal and distal CRCs. The use of antibiotics did not influence stool miRNA-221 and miRNA-18a levels.
Conclusions:
Stool-based miR-221 can be used as a non-invasive biomarker for the detection of CRC.

