Clinicopathologic and prognostic significance of overexpression of her-2/neu and p53 oncoproteins in gastric carcinoma using tissue microarray.

BACKGROUND The aim of the study was to verify the frequency of the immunohistochemical overexpression of her-2/neu and p53 in gastric carcinoma and their relation to the other clinico-pathological features and the impact on survival rates. PATIENTS AND METHODS A total of 93 patients of gastric carcinoma, who had a potential curative surgery in the period from 2001-2007 and with representative paraffin blocks, and sufficient follow-up data were included in this study. They were arrayed and evaluated for protein marker overexpression using tissue microarray (TMA). Patients, tumor and treatment characteristics were collected from the patients' files. The possible prognostic significance of p53 and her-2/neu over expression and different clinico-pathological features on survival rates were explored. RESULTS Twenty four (25.8%) cases were her-2/neu and p53 positive. None of the examined clinico-pathologic factors had a significant relation to her-2/neu overexpression. p53 was overexpressed in intestinal type, 14/34 (41.2%), more than in diffuse type, 10/59 (16.9%), (p= 0.01). There was no relation between the overexpression of p53 and her-2/neu. The median survival period was 17.7 months. The survival rates at 12 months were 64.2%, 52.2%, 55.6% and 45.0% for overall (OS), local control (LC), metastasis free survival (MFS) and disease free survival (DFS) rates, respectively. Patients with advanced stages had a significantly lower OS and MFS. Age above 57 years was associated with significantly lower OS, LC, MFS and DFS. Patients who received radiotherapy had significantly higher OS, LC, MFS and DFS. None of the survival rates had been affected by the overexpression of p53, or her-2/neu. CONCLUSION Although, this study failed to show any prognostic effect of p53 and her-2/neu on survival rates, we may suggest that p53 overexpression may play a role in the pathogenesis of intestinal gastric adenocarcinoma. It could also demonstrate the significantly improved survival rates with adjuvant chemoradiation. Also, TMA is a useful technique for rapid identification of protein expression profiles using minimal samples from archived tissues.