The value of diagnosis and prognosis prediction of serum miR-29a for colorectal cancer

Background and Objective:Colorectal cancer (CRC) remains one of the major cancer types and cancer related death worldwide. Sensitive, non-invasive biomarkers that can faciltate disease detection, staging and prediction of therapeutic outcome are highly desirable to improve survival rate and help to determine optimized treatment for CRC. MicroRNAs (miRNAs), have recently been identified as critical regulators for various diseases including cancer and may represent a novel class of cancer biomarkers. The purpose of this study was to investigate the value of diagnosis and prognosis prediction of serum miR-29a for colorectal cancer.Methods:Serum miR-29a was detected by using real-time RT-PCR, corresponding 50 CRC patients without metastasis, 48 CRC patients with liver metastasis and 50 healthy volunteers. They were a similar cohort of age- and sex-matched CRC patients without and with metastasis. The correlation between the expressions of serum miR-29a with clinical parameters of CRC patients was analyzed. The value of diagnosis and prognosis prediction of serum-specific miR-29a for CRC was evaluated.Results:Serum miR-29a was significantly higher in CRC patients than in controls(p<0.01).This marker yielded a cutoff value of 0.135, the sensitivity was 71.35% and the specificity was 83.96% in discriminating CRC patients from health controls. In addition, increased levels of miR-29a expression were also observed in colorectal tumors from colorectal liver metastasis patients compared with CRC patients(p<0.05).It yielded a receiver operating characteristic curve area of 0.855. At a cutoff value of 0.151, the sensitivity was 79.38%and the specificity was 85.26% in discriminating metastatic from non-metastatic patients. Conclusion:These findings suggest that serum miR-29a has strong potential as a novel noninvasive biomarker for early diagnosis of CRC patients and high levels of serum miR-29a were associated with poor prognosis. It may represent a novel and sensitive noninvasive biomarker in early diagnosis and prognosis prediction of colon cancer.