Correlations between histopathological and biological findings in nasopharyngeal carcinoma and its prognostic significance.

Forty-five consecutive cases of nasopharyngeal carcinoma were morphologically and immunocytochemically studied using monoclonal (anti-B and anti-T cell) and polyclonal (anti-S100 protein and antilysozyme) antibodies with the peroxidase-anti-peroxidase method to identify infiltrating lymphocytes (T and B cell) and histiocytes (monocytic/macrophagic and dendritic cells) in nasopharyngeal carcinoma. A variable density of dendritic cells was found within the tumor nests in 22 (49%) of 45 nasopharyngeal carcinomas examined; infiltrating macrophages were demonstrated in 15 (33%) specimens and around the tumor in almost all cases. Cases with moderate or marked density of dendritic cells (S100+) survived longer than those without such infiltration (mean 5-year survival rates of 31%, 55%, or 64% in patients with absent, moderate, or marked densities, respectively; P less than 0.05). A significant relationship between monocytic/macrophagic cells (lysozyme+) within the tumor and survival was also found (mean 5-year survival rate of 27% or 61% in patients with absent, moderate, or marked densities, respectively). However, lymphocytic infiltration was not statistically related to a better survival. Analyzing lymphocytic infiltration, we found a large prevalence of T cells in the neoplastic tissue without any prognostic significance. These data were correlated to different histological subtypes according to the principal histological classifications of nasopharyngeal carcinomas (Micheau, et al.; World Health Organization; Cologne University) to individualize the scheme which correlates best with prognosis and biological features of nasopharyngeal carcinomas. Our data suggest that, considering dendritic cells and macrophages within cancer nests, nasopharyngeal carcinoma histiotypes can be correlated to patient prognosis.