Correlation of p53 overexpression with the clinicopathological prognostic factors in gastric adenocarcinoma

Abstract

Background: Gastric cancer is one of the leading causes of cancer deaths. The etiology of gastric cancer is complex multistep process characterised by histopathologic precursor lesions and molecular genetic alterations involving APC, K-ras and p53 genes. Overexpression of p53 in gastric carcinoma is associated with bad prognosis. Aim: To establish correlation between p53 overexpression and clinicopathological features of gastric carcinoma. Materials and methods: A cross-sectional, descriptive hospital based study of clinical, histopathological and immunohistochemistry (IHC) features of gastric carcinoma was conducted on gastrectomy specimens received to the Department of Pathology from January 2008 to June 2013. The clinical features, tumour morphology and p53 status by immunohistochemistry, were evaluated in each case. Results: The most common histologic type of gastric carcinoma was of intestinal type and predominantly were grade III tumours (60%). Most (75%) of them presented with lymph node metastasis. Majority were in stage IIIA (27.5%) or stage IV (20.0%). Majority of gastric carcinomas (35%) had 1+ intensity of p53 expression but and it was not statistically significant. Majority of gastric adenocarcinomas showed p53 positivity in 5% tumour cells. Overall, 62.5% gastric adenocarcinomas showed p53 positivity and 10 out of 40 (25%) were intensely positive. There was no significant correlation between p53 status and age of patient, tumor site, tumor size, histological type, grade, lymph node status and TNM stage. Conclusion: Mutation in p53 plays a vital role in development of gastric carcinoma. However, a significant correlation between gastric carcinoma and clinicopathological parameters could not be established. A prolonged follow up study on a large number of cases can help to find out whether p53 overexpression by standard IHC could be a useful marker for prognosis of gastric carcinoma.