IMMUNOHISTOCHEMICAL ANALYSIS OF ADVANCED LARYNGEAL AND HYPOPHARYNGEALCARCINOMAS 3 DAYS AFTER APPLICATION OF MONOCLONAL-ANTIBODY AGAINST EPIDERMAL GROWTH-FACTOR RECEPTOR

Sixteen consecutive patients with stage III/IV laryngeal or hypopharyn geal 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 dissecti on. Presence of macrophages, T-cells (CD3) and T-cell subpopulations ( CD4/CD8), NK-cells, complement factors (iC3b, C1q, C4c), and expressio n of MHC class I, MHC class II, ICAM-1 and IL-2-R were determined in c ryostat sections of the surgical specimens and compared to normal tiss ue of the same patient. The antibody showed good binding to EGF-R of m alignant and normal tissue. However, no signs of strong inflammatory r eactions were noticed. Infiltration with macrophages was directly corr elated with the dose of the administered antibody, even in the basal l ayer of the normal mucosa. No morphological signs of direct destructio n of normal and malignant tissue infiltrated by macrophages or other i mmunocytes were noticed. This finding was underlined by random infiltr ation with HLA-DR positive-, T- and NK-cells. Possible long-term effec ts of this antibody - e.g. non-specific stimulation or improved antige nic processing - must be evaluated in further studies.