A study of Ki 67, p53 and their combination as immunomarkers in squamous cell carcinoma of oral cavity

Abstract

Background: Oral cancer is the most common cancer and constitutes a major health problem. Tobacco and alcohol remains the most important etiologic factors. Molecular level changes in the lesion occur before clinical and histopathological changes. The prognostic evaluation of this neoplasia is given by histological and immunohistochemical findings, including staging, histological grade, tumor size, lymph node involvement, immunohistochemical expression of p53 and Ki-67.In squamous cell carcinomas of oral cavity, p53 and Ki-67 are related to large tumors, metastasis to lymph nodes and very likely to a worse prognosis.Aim and objectives: To assess and compare the expression p53, Ki-67 and their combination markers in squamous cell carcinoma of oral cavity in relation to lymph node status, degree of histological differentiation and pathological staging. Materials and Methods: The prospective study was conducted in N.I.M.S medical college carried out with 108 cases of oral cavity squamous cell carcinoma with lymph node resection. The p53 and Ki-67 labelling indices were expressed as the percentage of Ki-67 and p53 immunolabelled tumor nuclei per 1000 tumor nuclei counted.Results: The maximum numbers of cases were found to be in the age group of 40-60 years (61.8%), mostly being men (85.1%). Female comprised of only 14.9% of the patients. All cases were subjected to immunohistochemical study for Ki-67 and p53. Positive expression of Ki 67 detected was in 92 cases and p53 was detected in 72 cases. Both Ki -67 and p53 were positive in 58 cases. Ki -67 marker was tested in all 108 cases. Out of total 108 cases 92 (85.2%) were found to be positive for Ki -67 and only 16(14.8%) were found negative. In the histological grading 48 (44.4%) were low grade (well differentiated), and 30 (55.6%), were high grade (moderately and poorly differentiated). Out of 48 low grade cases 14(29.2%) cases and out of 60 high grade cases 44(73.3%) were positive for p53and Ki 67 which was statistically significant The relationship of p53 and Ki -67 expression was statistically significant when compared with lymph node status. Conclusion: Male to female ratio was 5.7:1 with age ranging from 40-60 years. The most common site of squamous cell carcinoma was buccal mucosa followed by tongue in oral cavity. Positive expression of Ki 67 was detected in 92 cases and p53 positive expression was detected in 72 cases.