Coexpression of HER-2/neu and p53 is associated with a shorter disease-free survival in node-positive breast cancer patients

Breast cancer tissue was examined for overexpression of HER-2/neu and p53 oncogene proteins. Samples from 105 breast cancer patients were investigated by Western-blot analysis and their relationship to other established markers and clinical outcome was examined. In 21.0% of the cases HER-2/neu was overexpressed, and in 46.7% the p53 protein level was increased. Expression of these two oncogene products was closely correlated. Overexpression of both oncogenes was associated with larger tumour size and negative hormone receptor. The percentage of HER-2/neu and p53 overexpression was higher in node-positive patients, although statistical evaluation was not significant. While overexpression of HER-2/neu as well as p53 in node-positive patients was associated insignificantly with shorter disease-free survival, a significant difference could be documented when the disease-free survival of patients with overexpression of both oncogene proteins was compared to that of patients with no overexpression.