Breast cancer progression and expression of blood group-related tumor-associated antigens.

There is sufficient evidence that blood group related Lewis antigens are tumor-associated molecules. We have conducted immunohistochemical analysis of the expression of Lewis antigens in breast cancer tissue as an indicator of the degree of malignancy and as a prognostic factor. The studies were performed by examining 43 female patients diagnosed with invasive ductal carcinoma of the breast. Postoperative specimens were stained immunohistochemically using a panel of monoclonal antibodies (MAbs) specific for tumor-associated antigens: sialosyl LewisA, LewisA, LewisB, Lewisx, and LewisY. The aims of the study were to compare the appearance of metastases, degree of cancer stage (pTNM), and its histologic differentiation with the expression of Lewis phenotype. The evaluation of antigen expression was performed quantitatively and independently by two pathologists. Statistical significance was defined by Mann-Whitney test. The presented analysis of Lewis antigens showed higher expression of LeB and LeA (p = 0.03) in patients in stage N2 than in stage N1. The expression of LeB and LeY was higher in patients in stage T4 than in stage T1 (p = 0.02). No differences were observed for histologic differentiation. These data suggest that the expression of sialosyl-LeA and LeB antigens in breast cancer may predict metastases to lymph nodes.