Immunohistochemical evaluation of MUC1 mucin expression in non-small cell lung cancers

We investigated the immunohistochemical expression of carcinoma- associated MUC1 in human lung cancer tissues using the monoclonal antibody MUSE11. We also investigated the expression of sialyl-Lewis x (sLe(x)) using monoclonal antibody FH-6. According to the histological type of lung cancer, MUSE11 positivity was observed in 90% of patients with adenocarcinoma (72/80), 51.6% of patients with squamous cell carcinoma (49/95), and 54.5% of patients with large cell carcinoma (12/22). A significant difference was detected in the expression of MUSE11 between adenocarcinoma and the two other histological types. Thus, MUSE11 appears to be a candidate for a tumor- associated marker in patients with lung adenocarcinoma. There was no relationship between the expression of MUSE11 and T factors, N factors, pathological stage, grade of differentiation, or prognosis. A significant relationship was detected between the expression of MUSE11 and that of FH-6. Earlier studies have revealed that part of sLe is associated with the MUC1 polypeptide. Our results suggested that the relationship also existed in human lung cancer specimens.