CORRELATION OF PROGNOSIS OF BREAST-CANCER PATIENTS AND EXPRESSION OF LE(Y) WHICH ACTS AS A COFACTOR OF TUMOR PROCOAGULANT

Association between Le(Y) expression and prognosis of breast cancer wa s investigated using monoclonal antibody (MoAb) FS01, which recognizes Le(y) as an epitope, inhibits the procoagulant activity of cancer cel l-derived coagulating activity 1 (CCA-1). Expression intensity and pro coagulant activity of CCA-1, tissue factor and HLA-DR on breast cancer cell lines were also examined. Immunohistochemical staining of Le(y) was performed on primary lesions of 223 breast cancer patients who rec eived absolute curative operation. Flow cytometric analysis and clot t imer was used to detect expression and activity of each procoagulant o n cancer cell lines. The LeY expression was 73.5%, and no significant relation was observed between clinicopathological factors and intensit y of LeY expression. The group showing strong LeY positivity had a sig nificantly poorer prognosis than the Le(y)-negative group in 5-year di sease-free survival (p=0.019). Multivariate analysis using the Cox's p roportional hazards' regression model showed that Le(y) expression is an independent prognostic factor (p=0.018), following tumor size and l ymph node metastasis. LeY expression on cancer cell surface is higher than tissue factor and HLA-DR. FS01 and anti-tissue factor MoAb inhibi ted the coagulating activity of tissue factor-expressing lines, but no cells were inhibited by staphylococcal enterotoxin A, which is known to inhibit the coagulating activity of HLA-DR. CCA-1 and tissue factor plays a important role in the blood coagulating activity of breast ca ncer cell lines. Breast cancer patients are thought to have a poor pro gnosis because LeY expression on the surface of the cancer cell induce s blood coagulation via CCA-1.