Flow cytometric analysis of cell surface carbohydrates in metastatic human breast cancer.

Helix pomatia agglutinin (HPA)- and Concanavalin A (Con A)-binding carbohydrate expression were studied on 32 tumour samples from primary adenocarcinoma of the breast and 12 samples from lymph node metastases. Live cells were spilled from each of the fresh samples and the extent of fluorescent-labelled HPA and Con A-binding was assessed by flow cytometry. The extent of brightness was expressed in a defined quantitative fashion and the percentage of positive cells was accurately determined from a sample of 10,000 cells per tumour. Correlation of binding with clinicopathological features showed that HPA but not Con A related to lymph node involvement (P = 0.001) in tumours of higher grade (II and III). Spilled tumour cells (non-lymphocytes) were selected from the lymph nodes and the presence of HPA binding cells in the involved lymph nodes was found to relate to positive HPA binding in autologous primary tumours (P = 0.002). Dual-label analysis of HPA and Con A binding showed characteristic features for each tumour. The study demonstrates the use of flow cytometry as a simple and effective technique in detecting differences in lectin binding in live spilled cells from fresh breast cancer tissues. This method may prove to be particularly useful if performed preoperatively on cells in fine-needle aspirates.