Prediction of colorectal cancer relapse and prognosis by tissue mRNA levels of NDRG2

NDRG2 (N-Myc downstream-regulated gene 2) is aberrantly expressed in colorectal cancer (CRC) and related to tumor differentiation status. In the present study, we investigated the association between NDRG2 mRNA levels in primary CRC to determine whether levels of NDRG2 mRNA could predict relapse and survival. A hospital-based study cohort of 226 CRC patients was involved in the study. NDRG2 mRNA levels were determined by real-time PCR. Correlations of NDRG2 mRNA expression with tumor clinicopathologic features, disease-free survival, and overall survival of the patients were studied. Significant decreased expression of NDRG2 mRNA was detected in tumor specimens. NDRG2 mRNA expression significantly correlated with differentiation status (P < 0.001), lymph node metastasis (P < 0.001), and tumor node metastasis stage (P < 0.001). Patients with reduced level of NDRG2 mRNA had a statistically significantly shorter disease-free survival and overall survival duration than patients with preserved expression of NDRG2 mRNA. In multivariate analysis, NDRG2 mRNA level was found to be an independent prognostic factor for both disease-free survival and overall survival of CRC patients. The present research provided the first evidence that decreased NDRG2mRNAexpression in primary human CRC might be a powerful, independent predictor of recurrence and outcome.