HER 2/neu protein expression in colorectal cancer

Background: Conflicting data exist about the prevalence of HER-2/neu overexpression in colorectal cancer ranging from 0 to 83%. In our study we tried to clarify the extent of expression and its relationship to clinicopathological parameters. Methods: This study involved 77 specimens of malignant colorectal cancer lesions of surgically resected patients. HER-2/neu immunohistochemistry was performed using the Hercep-Test Kit. Results: Out of 77 specimens, 56 were Her-2/neu negative (70%), 20 (26%) showed a barely immunostaining (1+), only 1 (1%) was moderately (2+) and 2 (3%) were strongly positive (3+). Her2/ neu staining ( moderately and strongly positive) was only detected in primary tumours of patients with confirmed metastases. No relationship was found between membranous HER-2 expression and patients' gender or differentiation. The median survival time of patients with positive HER-2/ neu immunostaining was 21 versus 39 months in patients without HER-2/ neu expression ( p = 0.088). Conclusion: The c-erbB protein expression was observed in colorectal cancer but rarely in the therapeutic range ( 2+ and 3+). There was no significant association with tumour grade, gender, localization of the primary tumour or survival. These data indicate that c-erbB- 2 is unlikely to play a major role in the therapeutic management of colorectal cancer.