Evaluation of genotoxicity by micronucleus assay in oral leukoplakia and oral squamous cell carcinoma with deleterious habits

BACKGROUND: Oral cancer is the 12(th) most common cancer in women and the 6(th) in men. Of all oral malignancies, more than 92-95% is Oral Squamous Cell Carcinoma (OSCC). The high risk was due to Lifestyle-related habits such as smoking, alcohol consumption, chewing of areca nut related products which are considered as the major risk factors in OSCC. The exogenous carcinogens from tobacco smoke may induce a defective DNA damage response, which may alter the expression of genes that protect us against cancer that may result in genomic instability and this DNA damage can be assessed by studying the chromosomal aberrations, sister chromatid exchanges and the varied forms of the micronucleus. AIMS AND OBJECTIVES: The aim of this study was to evaluate the risk of development of oral leukoplakia (OLP) and OSCC due to DNA damage by studying micronuclei count in the east coast of Andhra Pradesh population with tobacco consumption habit and habit-free controls using Fluorescent microscopy. MATERIALS AND METHODS: A total of 60 subjects, 20 normal controls, 20 oral leukoplakia and 20 OSCC patients were selected from the outpatient patients of GITAM Dental College and Hospital, Rushikonda, Visakhapatnam and peripheral cancer hospitals in and around Visakhapatnam. Exfoliated cells were collected by giving 5-6 gentle strokes with spatula in a continuous unidirectional movement and then were uniformly spread on the previously cleaned microscopic slide. Fluorescent stain 4′, 6′-diamidino-2 phenylindole (DAPI) was used for MN analysis. RESULTS: Mean of cells with MN in controls, leukoplakia and OSCC cases was observed to be 1, 5.1,10.1 (F = 112.396, P < 0.001) respectively. Mean of the cells with MN in different grades of leukoplakia. (F = 35.594, P < 0.001) Mean of the cells with MN in different grades of OSCC. (F = 39.752, P < 0.001). CONCLUSION: The present study revealed an increase in mean frequency of cells with micronucleus from healthy individuals however similar studies in larger sample has to be done. This study concludes that MN index can be used as a screening test among high risk groups.