title: Reduction in HER-2 protein expression in a breast tumor HER-2 positive after only one injection of Trastuzumab: a case report.
abstract: HER-2 is overexpressed in 20 to 30% of breast cancer. Generally, metastases of a breast tumor have the same HER-2 status, although some discordances were reported.We report a case of reduction in HER-2 expression assessed by immunohistochemistry, following one day of a Trastuzumab injection, of a metastatic breast cancer to lymph nodes. Initially, the breast tumor HER-2 status was positive according to the same technique.We raise a hypothesis about technical interference and discuss the case in the framework of the existing literature.
authors.affiliation: Department of Medical Oncology, National institute of Oncology, Rabat, Morocco. i_elghissassi@hotmail.com
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Elghissassi
authors.forename: Hanane
authors.initials: H
authors.lastname: Inrhaoun
authors.forename: Stephane
authors.initials: S
authors.lastname: Vignot
authors.forename: Hind
authors.initials: H
authors.lastname: Mrabti
authors.forename: Hassan
authors.initials: H
authors.lastname: Errihani