Altered saccharide sequences in two groups of patients with metastatic prostatic carcinoma

To investigate the hypothesis that primary prostatic carcinomas with metastases to different sites (lymph nodes or bone) show varying expression of cell surface and cytoplasmic glycoconjugates.

A group of 14 patients with primary prostatic carcinoma with lymph node metastases but no bone metastases has previously been shown to have an increased survival time. This group was compared with a control group of 14 patients with lymph node-negative, bone metastasis-positive primary prostatic carcinoma using a panel of biotinylated lectins revealed by the avidin-biotin peroxidase complex method. The results were analysed semi-quantitatively and differences in binding patterns between the two groups were sought.

No significant differences were seen using the LCA, LTA, UEA-1, WFA, VVA or SBA lectins. The group with bone metastases but no lymph node involvement showed significantly increased binding for the ECA and AHA lectins, both before and after neuraminidase pre-treatment, compared with the lymph node-positive group.

These results suggest that tumours lacking or having a reduced affinity for binding sites for both Gal beta 1-3GalNac (Type I oligosaccharide structures--AHA) and Gal beta 1-4GlcNac (Type II oligosaccharide structures--ECA) sequences are more likely to develop lymph node metastases and less likely to develop bone metastases and thereby increasing the patient's chances of survival. This is further evidence that the metastatic potential of tumours per se and the ultimate site of distal metastases from such tumours is affected in part by the glycoconjugates expressed on their cell surfaces and indicates that metastatic phenotypes for prostatic carcinoma exists.