Prediction of lymph node involvement in breast cancer by detection of altered glycosylation in the primary tumour

Abstract

Axillary lymph node metastases at the time of diagnosis of breast cancer is the most accurate predictor of long-term prognosis. However, in patients treated by conservative surgery lymph node status often remains unknown. We have investigated the relation between changes in glycosylation of primary breast cancer cells, as judged by lectin binding, and the presence of axillary lymph node metastases. In a 24-year retrospective study, paraffin-embedded sections of 373 primary breast cancers were stained for the binding of Helix pomatia lectin (HPA). There was a strong association between HPA binding and presence of lymph node metastases, but no association with tumour size, histological grade, S-phase fraction, or patient age at diagnosis. This relation was confirmed by multiple regression analysis (in both survival and relapse free survival models) in which the prognostic significance of HPA binding was lost once nodal status had been introduced into the models. Life tables calculated for lymph-node positive versus lymph-node negative and HPA staining versus non-staining patients were almost identical over 15 years of follow-up. We propose that HPA recognises a glycoprotein that is associated with metastasis (to axillary lymph nodes and elsewhere) and poor prognosis in breast cancer. HPA binding to paraffin sections of primary tumour could aid difficult treatment decisions by providing an additional assessment of staging and likely long-term patient prognosis.