Fucosylated type-2 chain polylactosamine antigens in human lung cancer

Four specific monoclonal antibodies (MAbs) have been used to study distributions of fucosylated type-2 chain polylactosamine antigens, Lex, poly Lex, Ley and sialylated Lex-i antigens, in human lung cancer tissues and in the serum of patients with lung cancers. Radioimmunoassay frequently showed abnormally high antigen levels in the sera of 66 lung cancer patients tested. When histological typing was performed, high serum levels of the above 4 antigens were most frequently observed in patients with adenocarcinoma of the lung; i.e., after combining the results from the 4 antigens, 75% of the sera from patients with lung adenocarcinoma were positive (50% in the case of large-cell carcinoma, 30% in the case of squamous-cell carcinoma and 27% for small-cell carcinoma). Among the 4 antigens, the sialylated Lex-i antigen had the highest positive incidence, 58%, in the sera of patients with adenocarcinoma of the lung, compared to 33% for Ley, 29% for poly Lex, and 8% for Lex antigen. On the other hand, when the distributions of these antigens in the lung cancer tissues of 42 patients were studied by immunohistological techniques, the Ley antigen had the highest positive incidence, 100%, in lung adenocarcinoma tissues, poly Lex antigen had 86%, sialylated Lex-i antigen had 71%, and Lex antigen had 29%. In cancer tissues, the incidence of non-sialylated antigens, such as Ley, poly Lex and Lex antigens, often exceeds the positive incidence of the sialylated antigen, but the sialylated form of the antigen, such as sialylated Lex-i antigen, appears more often than the non-sialylated form in patients' sera.