Prognostic Role of Nucleophosmin in Colorectal Carcinomas

Abstract

Recent research suggests that nucleophosmin (NPM) may be a prognostic marker in colorectal carcinomas (CRC). We here tested its use to predict the survival of CRC patients. We investigated NPM expression by immunohistochemistry in histologically normal to malignant colorectal tissues and evaluated its association with clinicopathological variables. Overall and disease-free survival after tumor removal were calculated by the Kaplan-Meier method, and differences in survival curves were analyzed by the log-rank test. The Cox proportional hazards model was used for multivariate analysis of prognostic factors. NPM expression was found significantly upregulated in CRC compared to adjacent colorectal tissue, villous adenoma, tubular adenoma and normal colorectal mucosa (p<0.05 for all). NPM expression was statistically linked to cancer embolus, lymph node metastasis, differentiation grade, and recurrence of CRC. Overall and disease-free survival of NPM-negative CRC patients tended to be better than those for patients with NPM-positive lesions (log-rank statistic, p<0.05 for all). Multivariate analysis indicated NPM expression as an independent prognostic indicator for CRC patients (p<0.05 ). Our results suggest that NPM expression can predict the survival of CRC patients. Prognosis of CRC is determined by not only many known prognostic factors but also by NPM expression.