Extracellular matrix proteins expression and incidence of tumor infiltrating cells in laryngeal carcinoma.

Cryosections from surgical tissue blocks of primary laryngeal carcinoma were examined by immunohistochemistry for the distribution of several extracellular matrix (ECM) proteins and of tumor infiltrating cells (TIC). For the assessment of ECM proteins 8 monoclonal antibodies (Moabs) versus fibronectin, its neoplastic isoforms, tenascin, type IV collagen, laminin were used. TIC were evaluated by means of 9 Moabs versus various lymphocyte subsets, NK cells and macrophages. Marked differences were found in overall normal ECM proteins expression between tissues free from neoplastic invasion, those of closest tumor vicinity and of tumor mass. ECM proteins were found to be the most abundant in remote, apparently normal tissue compartments. They were less expressed in direct tumor proximity and almost absent from tumor mass. On the contrary, fibronectin isoforms were absent in tissue areas free from tumor but became demonstrable in tumor mass and its close vicinity. Tumor infiltrating cells were quite abundant in direct tumor vicinity. While comparing an intensity of expression of ECM proteins and accumulation of TIC in laryngeal carcinoma, reverse correlations were noticed. Strong expression of normal ECM proteins was accompanied by relatively scarce lymphocytic infiltrates in areas distant from primary tumor, while in the tissues abundant in TIC accumulation, such as in direct tumor vicinity, only weak ECM protein expression was seen. This was not the case when fibronectin neoplastic isoforms were studied. The latter could be shown in proximity or within tumor mass exclusively.