Role of expression of P63 and calponin in gastro-intestinal tract carcinomas

BACKGROUND: Gastrointestinal tract malignancies are causing significant morbidity and mortality constituting 27% of all cancer related deaths worldwide with highest burden of 62% in Asia. In developing countries like India, due to life style modifications and environmental factors the incidence of GIT malignancies are increasing nowadays. P63 and Calponin are the new immunohistochemical markers tried in GIT malignancies and the results were promising. So in our study, the expression of these two immunohistochemical markers were done and correlated with histopathological grading and lymph node status of these cases. OBJECTIVES: 1. To correlate the age, sex and anatomical site of distribution of gastrointestinal tract malignancies. 2. To study the histopathological features of gastrointestinal tract malignancies. 3. To study the role of expression of immunohistochemaical markers P63 and calponin in gastrointestinal tract malignancies. 4. To correlate the histopathological features with expression of immunohistochemical markers P63 and calponin. MATERIALS AND METHODS: A total of 60 cases of gastrointestinal tract carcinomas, 33 cases of GIT biopsies and 27 cases of GIT specimens were taken for the study. The study was conducted for three years (from June 2014 to June 2017). H & E sections and immunohistochemistry was done for the selected blocks of formalin fixed paraffin embedded sections. IHC done by using p63 and calponin for all the cases and the stastical analysis was done to evaluate the prognostic significance of these markers. RESULTS: In the present study, the most common age group involved in gastrointestinal tract malignancies was 61 – 70 years. Males are affected more than females with a sex ratio of 2.33:1. Stomach (antrum) is the most common anatomical site involved in GIT malignancies constituting 36.7% of all the cases followed by rectum with 16%.The most common histopathological diagnosis was adenocarcinoma, constituting around 88% of the total cases and the least common was malignant melanoma with 3.3%. The most common histopathological grade was moderately differentiated carcinomas constituting 36% of total cases (22 cases). The expression of IHC markers p63 and calponin were studied and compared with lymph node status and histopathological grade of tumors and the “p” values were found significant of < 0.05. p63 expression was found to be high in poorly differentiated carcinomas and calponin expression was low in poorly differentiated carcinomas. CONCLUSION: In this study, Increased expression of p63 is directly related to the lymph node metastases and the grade of the tumors. While calponin expression is inversely related to the grade and lymph node status of the cases studied. This study clearly showed that higher expression of calponin inhibits tumor metastases, tumor angiogenesis and tumor invasion, especially in patients with colorectal carcinomas. So targeted therapy with calponin will be prognostically beneficial to the patients with gastrointestinal tract carcinomas. Similarly p63 targeted therapy will be beneficial and improves the survival rate of the patients with gastrointestinal tract malignancies, especially in poorly differentiated esophageal carcinomas, gastric carcinomas and colorectal carcinomas