Monoclonal Antibody-defined Phenotypes of Regional Lymph Node and Peripheral Blood Lymphocyte Subpopulations in Early Breast Cancer

Abstract

Lymphocyte subset phenotypes in peripheral blood and axillary lymph node cell isolates from 28 patients undergoing surgery for breast cancer were determined by two-color immunofluorescence with monoclonal antibodies and flow cytometric analysis. Lymphocyte subpopulation proportions were determined with combinations of monoclonal antibodies directed against the Leu 2, Leu 3, Leu 7, Leu 8, Leu 11, Leu 12, Leu 15, Leu M3, and HLA-DR surface markers. Patients were staged according to the postsurgical-pathological modification of the Tumor-Node-Metastases staging system, for analysis of tissue source (lymph node versus peripheral blood) and stage of disease as factors influencing lymphocyte subset size. Activated Leu 2+DR+ and Leu 3+DR+ T-cells were elevated in Stage 2 carcinoma compared to Stage 1. Elevation of Leu 2+8+ circulating T-cells and a reciprocal depression of Leu 2+8- T-cells were also seen in Stage 2 patients when compared to Stage 1. Total T-cells, B-cells, Leu 2+, and Leu 3+ T-cell subsets and natural killer phenotypes defined by Leu 7 and Leu 11 were unchanged in the peripheral blood of Stages 1 and 2 breast cancer. Regional lymph nodes from Stage 1 were found to contain a high frequency of Leu 3+ cells which dropped significantly in Stage 2 patients; this was found to be numerically due to a sharp decrease in the Leu 3+8- subpopulation in Stage 2 patients. Elevated B-cells (Leu 12+), activated T-cells (Leu 2+DR+ and Leu 3+DR+), total Leu 2+ cells, and Leu 7-11+ natural killer cells were demonstrated in Stage 2 lymph nodes when compared to Stage 1. Generally, no differences in subpopulations were seen when level 1 (low axillary) lymph node cells were compared to level 3 (high axillary) lymph node cells at each stage of the disease. These findings demonstrate substantial differences in the profile of lymphocyte phenotypes between Stage 1 and Stage 2 breast carcinoma, especially in the ipsilateral regional nodes. The findings presented in this study suggest that changes in localregional immunocompetent cell subsets may be related to metastasis of tumor to the regional nodes and progression of disease without being fully reflected in the systemic circulation.