Relationship of transgelin expression with clinicopathological characteristics and disease-free survival in HER2-positive breast cancer

Background: Cancer-associated fibroblasts (CAFs) are essential for shaping the tumor microenvironment and influencing therapeutic responses in breast cancer. Thus, a better understanding of the expression of transgelin, a key marker of CAFs, may provide prognostic information. However, the prognostic significance of transgelin in human epidermal growth factor receptor 2 (HER2)-positive breast cancer remains unclear. Here, we investigated the relationship of transgelin expression with clinicopathological characteristics and survival outcomes in HER2-positive breast cancer. Methods: Data were collected retrospectively from 111 HER2-positive breast cancer tissue samples. The density of tumor-infiltrating lymphocytes (TILs) was evaluated by hematoxylin and eosin staining. Immunohistochemical staining of transgelin and CD8 was conducted. Results: Strong transgelin expression in CAFs was negatively associated with CD8 and TILs (p < 0.005). In the multivariate analysis, transgelin expression in CAFs (p = 0.023) and pathological stage (p = 0.029) were identified as independent prognostic factors for disease-free survival (DFS). The model combining transgelin expression in CAFs and pathological stage improved prediction (−2 log-likelihood = 74.062, Akaike information criterion [AIC] = 78.06) compared with pathological stage alone (−2 log-likelihood = 80.815, AIC = 82.81). Patients in the high-risk group had a shorter DFS (p < 0.0001). Conclusions: Transgelin expression in CAFs appears to be a novel prognostic marker for HER2-positive breast cancer.