p16 Tumour Suppressor Protein Expression in Oral submucous fibrosis using Immunohistochemistry - A clinicopathological study

DR NILEENA R KUMAR; DR ANITHA BALAN

Volume : VIII, Issue : V, May - 2019

p16 Tumour Suppressor Protein Expression in Oral submucous fibrosis using Immunohistochemistry - A clinicopathological study

Dr Nileena R Kumar, Dr Anitha Balan

Abstract :

Introduction: A lot of clinical and experimental research and epidemiological studies have been carried out in the field of oncology so far. Based on the current state of knowledge, these factors involved in carcinogenesis include a number of endogenous host factors and environments all malignancies. Epidemiological, molecular and statistical studies have suggested that between six and ten genetic events are required for head and neck cancer. These events are mainly genetic damage of proto–oncogenes, tumour suppressor genes, apoptotic genes and of those genes involved in DNA repair. Genetic abnormalities affecting Rb gene, p53 and p16 genes have been implicated in the early stages of head & neck squamous cell carcinoma. Hence this study was conducted to assess the p16 expression in oral submucous fiosis ,a common potentially malignant disease in our population. Methods: This study was conducted in the Department of Oral Medicine and Radiology, Dental College, Trivandrum, with the collaboration of the Division of Cancer Research, Regional Cancer Centre, Trivandrum, India .Patients were screened and those with clinical features suggestive of oral submucuous fiosis were selected for the study and Informed consent was obtained from all the patients. Instituitional ethics committee clearance was also obtained for the study. An incision biopsy of sufficient width and depth to ensure inclusion of connective tissue was taken from the buccal mucosa. Of the sections cut from formalin ﬁxed, parafﬁn embedded specimens, one was used for routine hematoxylin and eosin staining and the other was used for immunohistochemistry staining by Avidin and Biotin methods. The immunoreactivity was evaluated and the percentage of cells showing positive nucleus was determined. Results: The immunoreactivity of OSF was high in all the specimens with a mean expression of 37.24+– 1.1. The expression of P16 protein did not show any statistically signiﬁcant correlation with regard to age,and gender. When the habits of the patients were correlated with mean expression of p16,it was noted that the patients who practiced paan chewing either alone or in combination with smoking or alcoholism had a higher expression of p16 (34+_ 3.31).An increasing p16 expression was noted with the histologic grading in OSF , with the early lesions showing a p16 expression of 31.6+_2.54, moderately advanced lesion with a value of 37.77+_1.34 and advanced lesions giving a high p16 expression ,39+_2.However the results were not statistically significant. Conclusion: Further study of multiple biomarkers would aid the screening and identifying patients with premalignant lesion who are at a higher risk of transition to malignancy and could be selected for chemoprevention and intervention strategies aimed at reducing the progression of premalignant disease and will provide a target for designing novel therapeutics in oral cancer.