Apoptotic and mitotic indices in oral epithelial dysplasia and squamous cell carcinoma: A comparative study

BACKGROUND: Assessment of apoptotic cells and mitotic figures using light microscopy is an easy and viable alternative to assess tumour behaviour. AIMS: To evaluate apoptotic index (AI), mitotic index (MI) and apoptotic to mitotic index ratio (AI: MI) in different grades of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC) in haematoxylin and eosin-stained (H&E) sections. SETTINGS AND DESIGN: The study included 45 cases each of OED and OSCC cases which were further subgrouped into groups of 15 each based on their grades. AI, MI and AI/MI were assessed and compared with 15 cases of normal mucosa. METHODS AND MATERIAL: Apoptotic cells and mitotic figures were counted using a binocular light microscope equipped with an oculometer grid (20 × 20 squares) on the eyepiece. Cells were counted in 15 grid fields under oil immersion lenses (×100) in a stepladder fashion. AI/MI ratio was calculated. STATISTICAL ANALYSIS: The results obtained were statistically analysed using Analysis of variance and Tukey Honestly Significant Difference tests with SPSS 20 software at a 0.05 significance level. RESULTS: AI increased with increasing grades of dysplasia and decreased with increasing grades of OSCC. MI increased with increasing grades of OED and OSCC. AI/MI increased with increasing grades of OED but decreased with increasing grades of OSCC. CONCLUSION: In the light of the current observations, AI, MI and AI: MI can be considered as valuable parameters to assess the biological behaviour of OED and OSCC.