Leukocyte composition of human breast cancer

B Ruffell, A Au, HS Rugo… - Proceedings of the …, 2012 - National Acad Sciences
Proceedings of the National Academy of Sciences, 2012National Acad Sciences
Retrospective clinical studies have used immune-based biomarkers, alone or in
combination, to predict survival outcomes for women with breast cancer (BC); however, the
limitations inherent to immunohistochemical analyses prevent comprehensive descriptions
of leukocytic infiltrates, as well as evaluation of the functional state of leukocytes in BC
stroma. To more fully evaluate this complexity, and to gain insight into immune responses
after chemotherapy (CTX), we prospectively evaluated tumor and nonadjacent normal …
Retrospective clinical studies have used immune-based biomarkers, alone or in combination, to predict survival outcomes for women with breast cancer (BC); however, the limitations inherent to immunohistochemical analyses prevent comprehensive descriptions of leukocytic infiltrates, as well as evaluation of the functional state of leukocytes in BC stroma. To more fully evaluate this complexity, and to gain insight into immune responses after chemotherapy (CTX), we prospectively evaluated tumor and nonadjacent normal breast tissue from women with BC, who either had or had not received neoadjuvant CTX before surgery. Tissues were evaluated by polychromatic flow cytometry in combination with confocal immunofluorescence and immunohistochemical analysis of tissue sections. These studies revealed that activated T lymphocytes predominate in tumor tissue, whereas myeloid lineage cells are more prominant in “normal” breast tissue. Notably, residual tumors from an unselected group of BC patients treated with neoadjuvant CTX contained increased percentages of infiltrating myeloid cells, accompanied by an increased CD8/CD4 T-cell ratio and higher numbers of granzyme B-expressing cells, compared with tumors removed from patients treated primarily by surgery alone. These data provide an initial evaluation of differences in the immune microenvironment of BC compared with nonadjacent normal tissue and reveal the degree to which CTX may alter the complexity and presence of selective subsets of immune cells in tumors previously treated in the neoadjuvant setting.
National Acad Sciences