Prognostic Potential of Argyrophillic Nucleolar Organizer Regions (Agnors) in Oral Lesions: A Systematic Review

Abstract

Early detection of oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) is important for dental professionals to improve patient survival rates. More than half of patients with oral squamous cell cancer had advanced disease at the time of diagnosis, indicating a lack of early detection and risk assessment biomarkers. The development of new protein biomarkers will help in early diagnosis and treatment.The argyrophilic nucleolar organiser regions (AgNORs) staining technique is simple and cost-effective. These are replicatory markers that identify epithelial dysplasia. And it also plays a very important role in differentiating the benign, pre-malignant, and malignant lesions of the oral cavity. The number of AgNORs per cell has been considered an indicator of cellular proliferative activity. Microscopically, NORs can be identified as well-defined black dots located throughout the cell nucleus. The agNOR quantity is strictly proportional to the proliferative activity of the cell. AgNOR quantification helps in the determination of the degree of epithelial dysplasia and, consequently, in the analysis of its potential for malignant transformation. AgNOR qualitative characteristics help in differentiating hyperplastic, premalignant, and malignant oral lesions. The sliver staining technique is useful for studying the structure of the nucleolus as well as the variations in its activity. AgNORs are a valuable parameter in tumour pathology.