[Immunologic modulation of tumor aggressiveness in cancer of the larynx. II. Clinicopathologic correlations with the loss of expression of the HLA ABC antigens]. / Modulación inmunológica de la agresividad tumoral en el cáncer de laringe. II. Correlaciones clinicopatológicas con la pérdida de expresión de antígenos HLA ABC.

A series of 60 primary laryngeal and hypopharyngeal tumours, 24 lymph node metastases and normal tissue were evaluated in frozen sections for the expression of MHC class I antigens, using monoclonal antibodies. We found 13 cases presenting total HLA-ABC losses, 5 selective losses of HLA-A antigens and 1 of HLA-B antigens. We were able to find statistical association between these losses and a number of clinical and pathological parameters, such as T and N stage, degree of differentiation, scores according to Jakobsson and Glanz grading systems, vascular invasion or leukocytic infiltrate. Our results lead us to the following conclusions: a) HLA class I losses were found in a group of tumours showing a greater aggressiveness and worse prognosis; b) these alterations in the expression are not associated with a increased metastatic potential. Thus, the absence of HLA molecules in laryngeal tumours is related to a greater local aggressiveness, and the loss of class I antigens seems to constitute and adaptive tumour mechanism to avoid the different anatomical and immunological barriers present in the laryngeal organ.