Immunohistochemical p53 overexpression correlated to c-erbB-2 and cathepsin D proteins in colorectal cancer

The immunohistochemical overexpression of p53 protein in 42 large bowel cancers was correlated to c-erbB-2, cathepsin D (CD) proteins and other clinical and prognostic parameters. p53 overexpression (found in 60% of specimens) was positively associated with cathepsin D staining in stromal cells from older patients and better differentiated colorectal carcinomas (G1+G2). Cytoplasmic staining of c-erbB-2 protein was found in 58% of cases. No staining was observed at the cell membrane level. Our findings suggest that lower p53 expression in G3 carcinomas may be due to a high genomic instability, with the loss of both alleles of the gene. Therefore, these carcinomas were immunohistochemically silent. Although our series was small, the association between p53 nuclear neoplastic cells and CD stromal cells is interesting as regards the possible implications of these markers in colorectal cancer.