Upregulated NPM1 is an independent biomarker to predict progression and prognosis of oral squamous cell carcinomas in Taiwan

Background Nucleophosmin/nucleoplasmin family 1 (NPM1) has broad physiological functions, such as DNA replication, transcription, ribosome biogenesis, and centrosome replication. This study explored the clinicopathological importance of NPM1 as a prognostic marker for oral squamous cell carcinoma (OSCC). Methods We collected specimens from 96 OSCC, 45 oral epithelial dysplasia (OED), and 29 normal oral mucosa (NOM). NPM1 expression was analyzed via immunohistochemistry. Correlations between NPM1and clinical parameters were analyzed using Student t test, chi-squared test, and Kaplan-Meier product-limit method. Results The NPM1 labeling indices (LIs) were significantly higher in OSCCs than in NOM and oral OED. Higher NPM1 expression was significantly correlated with larger tumor size, nodal metastasis, and advanced clinical stage. Multivariate analysis revealed that higher NPM1 LIs were an unfavorable independent factor for survival. Conclusions Upregulated NPM1 is an independent biomarker of poor prognosis and NPM1 inhibitors may be promising in molecular targeted therapy against OSCC.