[Immunohistochemical studies of advanced laryngeal and hypopharyngeal carcinomas 3 days after administration of monoclonal antibody against epidermal growth factor receptor].

Sixteen consecutive patients with stage III/IV laryngeal or hypopharyngeal cancer received 0, 20, 100 or 400 mg i.v. of the murine anti EGF-R IgG2a mab EMD 55900 three days before laryngectomy and neck dissection. Presence of macrophages, T-cells (CD3) and T-cell subpopulations (CD4/CD8), NK-cells, complement factors (iC3b, C1q, C4c), and expression of MHC class I, MHC class II, ICAM-1 and IL-2-R were determined in cryostat sections of the surgical specimens and compared to normal tissue of the same patient. The antibody showed good binding to EGF-R of malignant and normal tissue. However, no signs of strong inflammatory reactions were noticed. Infiltration with macrophages was directly correlated with the dose of the administered antibody, even in the basal layer of the normal mucosa. No morphological signs of direct destruction of normal and malignant tissue infiltrated by macrophages or other immunocytes were noticed. This finding was underlined by random infiltration with HLA-DR positive-, T- and NK-cells. Possible long-term effects of this antibody--e.g. non-specific stimulation or improved antigenic processing--must be evaluated in further studies.