[Comparative immunohistochemical study of invasive duct carcinoma and Paget's disease of the breast with c-erbB-2 overexpression].

Overexpression of c-erbB2 oncogen is observed in 90-100% of cases of Paget's cancer. In all cases, the overexpression is caused by gene amplification. The authors carried out an immun ohistochemrical study of c-erbB2 (HER2/neu)-positive breast tumors: Paget's cancer (and hence with gene amplification) and breast invasive duct cancer without gene amplification. Moreover, the authors identified a case of c-erbB2-negative Paget's cancer, the phenotype of which was compared with the phenotypes of two earlier groups of tumors. The findings suggest that only formation of c-erbB2 heterodimers that cannot cause an increase in proliferation on their own is observed in the study groups of tumors.