EGF-R and Her2/neu overexpressing tumors: independent collectives for treatment of breast cancer by specific monoclonal antibody-therapy.

PURPOSE: In our recent studies, we demonstrated that breast cancer treatment by anti-EGF-R antibody resulted in a significant therapeutic effect in vivo. Furthermore, we were able to elucidate histopathologic parameters with an impact on therapy success. The aim of this study was the evaluation of EGF-R and Her2/neu protein expression on a large series of primary breast cancer, to elucidate if anti-EGF-R antibody therapy is a new therapeutic option for patients who are Her2/neu negative and where, therefore, anti-Her2/neu antibody treatment is not applicable. METHODS: We analyzed EGF-R and Her2/neu protein expression of 149 consecutive primary breast cancer specimens by fully quantitative enzyme-linked immunosorbent assay. For evaluation of stochastic independence, we used chi(2)-test as goodness-of-fit test. RESULTS: We found EGF-R and Her2/neu expression as stochastically independent in primary breast cancer. CONCLUSIONS: Anti-EGF-R antibody treatment is a potential therapeutic option for patients with Her2/neu negative breast cancer.