Expression of p53 protein in gastric cancer: an immunohistochemical study with correlation to proliferative activity

Immunohistochemical detection of p53 was performed by using the monoclonal antibody D0-7 (IgG2b) in 52 gastric cancers. Positive staining was detected in 42% (22/ 52) of the cases. There was no significant correlation between p53 expression and parameters such as age, sex, location, histological type, size, tumor grade depth of invasion, product of mucus and lymph node metastases. The nuclear p53 immunoreaction was closely associated with necrosis (p < 0.05) and vessel invasion (p < 0.05). For the estimation of proliferative activity, proliferating cell nuclear antigen labelling index (PCNA-LI) and Ki-67-LI on paraffin and frozen sections were immunohistochemically measured. A significant positive correlation was found between PCNA-LI and p53 tissues' immunoreactivity. There was a significant correlation in the depth of tumour invasion (p < 0.05) and PCNA-LI, and a small correlation of with grade (p = 0.075) and vessel invasion (p = 0.078). No significant association could be established with any clinicopathological parameters and Ki-67-LI. These results suggest that the p53 gene may be play an important role in the expansion of gastric carcinoma and in the proliferative activity, as determined with PCNA-LI.