Immunohistochemical Study of c-erbB-2 Protein in Colorectal Cancer and the Correlation with Patient Survival

We related events in immunohistochemical studies on formalin-fixed, paraffin-embedded preparations of 146 colorectal cancer patients. One hundred (68.5%) revealed cytoplasmic staining and only 3 of the 100 showed membranous staining. Western blot analysis revealed proteins with molecular masses of 185 and 155 kD following immunohistochemical membranous and cytoplasmic staining, but only a 155-kD protein following cytoplasmic staining. Amplification of the c-erbB-2 gene was detected in 2 of 44 cases (4.5%). Cytoplasmic c-erbB-2 overexpression correlated with tumor size (p