Clinicopathological significance of erbB-2 expression in colorectal carcinoma.

The level of erbB-2 expression in both the tumour tissue and serum of individuals with colorectal carcinoma is unclear. This study aims to clarify expression levels and to relate these to a range of clinicopathological parameters. Overexpression of erbB-2 was detected in 25% of patient tumour tissue and an elevation in serum concentration of the extracellular domain (ECD) of erbB-2 was detected in 10% of patients. Surprisingly, an elevated serum ECD concentration did not correlate with erbB-2 overexpression within the primary tumour, and neither tumour or serum levels of the protein correlated with any clinicopathological parameters examined. These results indicate that erbB-2 overexpression in tissue and serum are not uncommon in colorectal carcinoma, but may not be useful as predictors of disease outcome.