The immunohistochemical Galectin-3 expression in tumor and cancer-associated fibroblasts in invasive ductal carcinomas of breast and their relationship with clinicopathological parameters

Background: Galectin-3 has an important role in metastasis, therefore, Galectin-3-focused therapies have attracted attention for various cancers. Aim: We aimed to reveal the relationship between the expression of Galectin-3 within the tumor/cancer-associated fibroblasts (CAF) and clinicopathological parameters in patients with invasive ductal carcinomas. Materials and Methods: Hematoxylin and eosin-stained slides of breast excision materials diagnosed between 2010 and 2016 were re-examined retrospectively. Accordingly, 118 cases (luminal group = 58, Human epidermal growth factor receptor 2 (HER2) group = 27, and triple-negative breast carcinoma group [TNBC] =33 cases) were included. Galectin-3 levels were evaluated with a calculated H-score in tumor and semiquantitatively in CAFs. Statistical Analysis: Data was analyzed with t-tests and Chi-square tests. Kaplan-Meier and Log-rank tests were used for survival analysis. Results: The presence of Galectin-3 expression in CAFs but not in the tumor was associated with the greater number of axillary metastatic nodes and advanced pN stage. The loss of Galectin-3 expression in CAFs was more frequent in TNBC. There was no significant relationship between the expression level of Galectin-3 and survival status. However, in most of the cases with distant metastasis or patients who died, Galectin-3 was negative in the tumor, whereas it was positive in CAFs. Conclusions: The expression of Galectin-3 in tumors and CAFs may have a role in metastasis to axillary lymph nodes and distant sites. In terms of molecular subtype, TNBCs show a relationship with Galectin-3 negativity in CAFs.