Galectins are commonly overexpressed in
cancer cells and their expression pattern is often associated with the aggressiveness and metastatic phenotype of the
tumor. This study investigates the prognostic influence of the expression of galectin7 (Gal-7) and galectin8 (Gal-8) in
tumor cell cytoplasm, nucleus and on surrounding immune cells. Primary
breast cancer tissue of 235 patients was analyzed for the expression of Gal-7 and Gal-8 and correlated with clinical and pathological data and the outcome. To identify immune cell subpopulations, immunofluorescence double staining was performed. Significant correlations of Gal-7 expression in the cytoplasm with HER2-status, PR status, patient age and grading, and of Gal-8 expression in the cytoplasm with HER2-status and patient age and of both
galectins between each other were found. A high Gal7 expression in the cytoplasm was a significant independent prognosticator for an impaired progression free survival (PFS) (p = 0.017) and distant disease-free survival (DDFS) (p = 0.030). Gal-7 was also expressed by
tumor-infiltrating macrophages. High Gal-8 expression in the cytoplasm was associated with a significantly improved overall survival (OS) (p = 0.032). Clinical outcome in patients showing both high Gal-7 and with low Gal-8 expression was very poor. Further understanding of the role of
galectins in the regulation and interaction of
tumor cells and macrophages is essential for finding new therapeutic targets.