Langerhans cells in nasopharyngeal carcinoma in relation to prognosis.

Langerhans cells (LC) and macrophages in 119 cases of nasopharyngeal carcinoma and 19 cases of nasopharyngeal mucosa obtained from non-cancer patients were studied by SPA immunohistochemical methods with the use of antibodies against S-100 protein and lysozyme, respectively. The distribution of LC in the tumor tissue was different from that in macrophages. Patients with dense infiltration of LC in the tumor tissue survived longer than those without such infiltration (mean survival times, 26.9, 51.7 and 72.6 months in the patients with -, + and ++ density, respectively: P < 0.005). There was no relationship between patient prognosis and density of macrophages (P > 0.25). LC may play an important role in tumor immunity and may be taken as one of the criteria of prognosis.