Changes in protein glycosylation of tumour cells, as detected by
lectin histochemistry, have been associated with
metastasis formation in several human
malignancies. This study analysed the association between
lectin binding and
metastasis in
cutaneous malignant melanoma. In a 10-year retrospective study, sections of 100 primary
cutaneous malignant melanomas were histochemically stained for the following 5
lectins: HPA, SNA-I, MAA, WGA and
PHA-L, differing in their
carbohydrate specificity. Since differences in the results of HPA binding depending on methodology have been reported, an indirect and a biotinylated method were employed for HPA. Kaplan-Meier analysis of time to first
metastasis revealed a positive correlation between HPA binding and
metastasis for both methods, with the biotinylated HPA method (P< 0.0001) being superior to the 'indirect' method (P = 0.0006). Cox regression analysis demonstrated that even after adjustment for stage, HPA positivity is an independent predictor for
metastasis. The results of the present study indicate that N -acetyl-
galactosamine/-
glucosamine residues, recognized by HPA, are linked to
metastasis in
malignant melanoma. In contrast, beta1-6 branched
oligosaccharides or
sialic acid residues, both of which were correlated with
metastasis in other
malignancies, are of no functional importance for
metastasis formation in
malignant melanoma. Thus, HPA proved to be a useful and independent prognostic marker for the metastatic phenotype of
melanoma.