p53 is an indicator of tumor progression in early but not advanced gastric carcinomas.

ABSTRACT

BACKGROUND/AIMS: p53 plays an important role in the development of gastric carcinomas through its effect on apoptosis. Its use as a biomarker of tumorigenesis and progression in clinical tissue is currently under consideration. This project assessed its value in early and advanced stage gastric carcinomas. METHODOLOGY: The characteristics of positive staining for p53 was evaluated in 202 gastric adenocarcinomas classified into early stage (T1) (127 cases) and advanced stage (T2, 3 and 4) (75 cases) using the tumor-node-metastasis classification. Four subgroups (classified as p53 negative, +, ++ and +++ according to the level of positivity) were investigated for relationships with apoptosis (morphology) or cell proliferation (Ki-67). RESULTS: The mucosa of early stage and both mucosa and subserosa of advanced cancers were examined. p53-positive early stage cancers had more apoptosis but also more proliferation than p53-negatives (P<0.05), perhaps indicating conferral of a growth advantage. In advanced cancers, there was no correlation between apoptosis and extent of p53 positivity. p53 positivity had no correlation with cell proliferation in the mucosa and subserosa of these cancers. CONCLUSIONS: p53 may be useful as an indicator of development and progression in early stage gastric cancers but this is not the case for advanced stage gastric cancers.