Divergence in distribution and prognostic significance of major basement components in laryngeal carcinomas.

In previous studies, we demonstrated a loss of major basement membrane (BM) components in laryngeal squamous cell carcinomas and provided initial evidence that this was of potential prognostic significance. In our current study, we extended the panel of BM antibodies and enlarged our study group in order to perform a multivariate statistical analysis. We analyzed 26 laryngeal squamous cell carcinomas immunohistochemically for the distribution of the BM-components collagen IV, collagen VII, laminin-1, laminin-5, perlecan and fibronectin. The resulting data were correlated with clinical prognostic factors and statistical correlation coefficients were determined for independent uni- and multivariate analysis. All carcinomas analyzed revealed defects of the peritumoral BM with more extensive loss of collagen VII than collagen IV, laminin-1, perlecan and fibronectin. Laminin-5 in contrast was present even in poorly differentiated tumors showing an enhanced intracytoplasmatic staining in the tumor cells. Furthermore, our statistical analysis did not show independent prognostic significance of any of the BM-components. Our observations indicate a divergence between the loss of several major BM-components (collagens IV, VII, laminin-1, perlecan) and an enhanced deposition of laminin-5. This suggests a severely altered cell-matrix interaction, since laminin-5 links the collagen VII-containing anchoring fibrils to cell receptors of the integrin type.