Immunohistochemical Expression of p53 in Squamous Cell Carcinoma of the Lip (A Clinicopathological Study)

Abstract

Lip carcinoma is most commonly seen after skin carcinoma in the head-neck region. Mutation of the p53 gene has been reported in a variety of human malignant tumors like squamous cell carcinoma (SCC) and is frequently associated with over expression of p53 protein.The purpose of this study was to analyze the immunohistochemical over expression of p53 in SCC of the lip in relation with the clinicopathologic pictures.The materials used in this study consist of (40) formalin fixed, paraffin-embedded lip biopsy specimens of squamous cell carcinoma. p53 immunoreactivity was evaluated in 1000 cells examined under the microscope at 40 magnification and recorded as percentage of p53 positive tumor cells in relation to different clinical and histopathological factors. The p53 index for squamous cell carcinoma of the lip was ranging between 0.5%-58%, and (72.5%, 29 case) showed positivity for p53 and (27.5%, 11 case) were negative. The highest number and percentages of p53 positive cases were seen associated with males (74.19%), ≥60 year’s age group(73.33%), patients with outdoor occupations (100%), upper lip (75.0%), >2cm size lesions(73.68%), patients with palpable lymph node (74.91%), moderately and poorly differentiated type (77.78%), and positive involvement of surgical margins (78.57%). Statistical analysis showed no significant relation of the mean labeling indices with the sex, site, tumor size, the presence or absence of palpable lymph node, grade of differentiation, and involvement of surgical margins(p>0.05), but it showed significant relation with the patient age and occupation (p<0.05). The old age patients (≥60 years) and patients with outdoor occupations showed the highest p53 labeling index significantly.