The Prognostic Significnce of p53 Protein Overexpression in Gastric Carcinoma

Rhee, Jeong Kyun

Abstract

To evaluate prognostic significance of p53 gene mutation and p53 protein overexpression, 83 cases of primary gastric carcinoma (stage 1b, II, and III) were analyzed. Immunohistochemical assay using labeled streptavidine biotin method and mouse Anti-P53 was done on paraffin embedded tissues. The overall 5-year survival rate was 54.2%. Depth of invasion, lymph node metastasis, and stage were the prognostic factors (p<0.05). p53 was positive in 33 cases(39.8%). There were no significant association between p53 expression and other parameters such as age, sex, tumor location, size, gross finding, histologic type, depth of invasion, lymph node metastasis, and stage. The 5-year survival rates of p53 positive and negative groups were 62% and 42.4% respectively (p=0.0657). Survival distribution for p53 adjusted for location and depth of invasion showed significant difference. Five-year survival rates were 55%, 25%, 0% in p53 positive groups and 65.4%, 65%, 28% in negative groups at the lower, middle, and upper portion of the stomach, and 53.9%, 36.9%, 0% in p53 positive and 77.3%, 53%, 0% in negative groups in t2, t3 and t4. In comparison of 5-year survival rates of p53 positive and negative groups in the same stage, p53 positive groups showed worse prognosis than the negative, but they were not significant statistically. There were 57.1%, 92.9% in stage 1b (p=0.0678), 50%, 61.1% in stage II, 42.9%, 42.9% in stage IIIa, and 14.3%, 25% in stage IIIb respectively. So overexpression of p53 protein has little prognostic significance.