SIGNIFICANCE OF MUC1 AND MUC2 MUCIN EXPRESSION IN COLORECTAL-CANCER

Aims-To compare the lineage specific distribution of MUC1 and MUC2 muc ins in normal colorectal mucosa and adenocarcinoma and to identify pat hological correlations. Methods-Paraffin wax sections from 51 colorect al cancers were examined for the expression of MUC1 and MUC2, non-O-ac etyl sialic acid and the carbohydrate epitopes Le(x), Le(y), sialosyl- Le(x), sialosyl-Tn, and Tn using standard histochemical methods. Resul ts-MUC1, Le(x) and Le(y) co-localised with columnar cell secretions, w hereas MUC2, mild periodic acid Schiff and sialosyl-Tn co-localised wi th goblet cell mucin in both normal and malignant tissues. Sialosyl-Le (x) and Tn were associated with both Lineages. In normal tissues MUC1, Le(x) and Ley showed only trace expression by crypt base columnar cel ls. Cancers could be classified into four phenotypes (MUC2+/MUC1-, MUC 2+/MUC1+, MUC2-/MUC1+, MUC2-/MUC1-). Particular phenotypes showed sign ificant correlations with cancer type, lymph node spread and peritumor al lymphocytic infiltration and trends falling short of significance i n relation to grade of differentiation and contiguous adenoma. Conclus ions-Classification of colorectal cancer by means of lineage specific function may be relevant to both pathogenesis and prognosis.