Histological significance of p53 gene expression in squamous cell carcinoma of the buccal mucosa

Introduction Oral Squamous Cell Carcinoma (SCC) results from genetic mutations which activate the oncogenes and inactivate the tumor suppressor gene namely TP53. Despite the use of multimodality treatments the prognosis of oral SCC has not changed significantly. Purpose To evaluate 1) if there is any correlation between the two prognostic indicators i.e. p53 over expression and histological grade of the tumor 2) if any of the parameters of histological grading correlate significantly with p53 over expression. This information would help in understanding the exact role of TP53 gene mutation in cellular progression of oral SCC. Method Study was conducted on 90 resected specimens of Stage IV SCC of buccal mucosa. Slides from these specimens were evaluated for histological grading by Anneroth’s method and p53 over expression by Immunohistochemistry. Results Statistically significant co-relation was seen between the total histological grade and p53 over expression. Also 4 individual histological parameters which indicated high cellular turnover were also significantly associated with p53 over expression. Conclusion TP53 mutation histologically signifies an early event in cellular progression of oral SCC.