ASSESSMENT OF P63 EXPRESSION AND ITS ASSOCIATION WITH HISTOLOGICAL GRADING OF ORAL SQUAMOUS CELL CARCINOMA

Rumana Mahmud*, Purabi Sarkar, Syeda Nabila Islam Juthee, Md. Hasnain Mahbub, Mohammed Fazla Alahi and Md. Zillur Rahman

ABSTRACT

Background: Oral cancer constitutes the sixth most common cancer worldwide and third most common cancer in South-East Asia. Pathologists have played a major role in identifying different histological and immunohistochemical markers that have a direct bearing on both the behavior and treatment of oral cancer. P63 overexpression has been studied as a prognostic and therapeutic target in oral squamous cell carcinoma. The aim of the present study was to evaluate the immunohistochemical expression of p63 and its association with histopathological grading of oral squamous cell carcinoma. Material and Method: This cross-sectional study was conducted in the Department of Pathology, Chittagong Medical College over a period of 21 months. Specimens from 58 patients were fixed in 10% neutral buffered formalin and embedded in paraffin. Haematoxylin and Eosin stained slides of each case was prepared from each paraffin block for proper evaluation of tumor type and grade. Two slides were prepared from representative tumor blocks of each specimen and stained with primary antibodies against p63 (mouse monoclonal Ab-1; DAKO Denmark). Finally the association between histological grading and p63 expression was assessed by Chi-square test and later intergroup analysis was done between different grades of squamous cell carcinoma by bonferroni test. Result: The mean age of the patients with breast carcinoma studied was 56.98 ± 12.96 years, years ranging from 30 to 80 years; the majority of the cases (62.1%) were of grade I. Among the 58 patients, maximum were grade I with low p63 expression in 23 cases (39.6%) but grade II and grade III were high p63 expression respectively in 17 cases (29.3%) & 3 cases (5.17%).There was statistically significant association between p63 expression and grading of OSCC whereas no significant relationship was detected between markers immunoreactivity and patients age, gender, tumor location and other risk factor. In post hoc analysis, significant association found between grade I and grade II (p=0.0001) and also significant between grade I and grade III (p=0.002). No significant association was observed between grade II and grade III (p=1.00) of OSCC. Conclusion: The immunohistochemical evaluation of p63 overexpression significantly associated with higher grade of OSCC. So it can be used as a prognostic marker and potential targeted therapy of OSCC. Larger sample sizes using standardized tests are needed to understand the exact biological role of p63 in this type of carcinoma.

Keywords: Oral cancer, Oral squamous cell carcinoma, Poor hygiene, Poor diet.