Significance of Silver-stained Nucleolar Organizer Regions in Early Diagnosis and Prognosis of Oral Squamous Cell Carcinoma: A Multivariate Analysis

Abstract

Argyrophilic nucleolar organizer regions (AgNORs) appear to be of diagnostic and prognostic significance in different types of human tumour. The present study examined the AgNOR counts in normal, premalignant and malignant oral mucosa to evaluate their potential as a biological marker for tumour progression and a prognostic predictor for treatment outcome in oral carcinomas. The Spearmann's rank correlation analysis between AgNOR counts and various stages of tumour progression in oral mucosa exhibited a highly significant positive coefficient (r_s=0.7969; p≤0.001), thus indicating the role of AgNORs in the early diagnosis of potentially malignant oral leukoplakia. When analyzing the prognostic significance of AgNOR in oral carcinomas, mean count >2.8 concurred with poor prognosis in both univariate and multivariate analysis. Along with AgNOR counts, the T-status of disease was also found to be an independent predictor for treatment outcome in multivariate analysis. Thus T3 and T4 tumours, with mean AgNOR counts more than 2.8, are aggressive and may exhibit resistance to current treatment protocols.