AbstractEmerging evidence indicates that Fascin-1 (FSCN1) may possess a causal role in the development of several types of cancers and serves as a novel biomarker of aggressiveness in certain carcinomas. However, the regulatory mechanism of FSCN1 in triple-negative breast cancer (TNBC) cell invasion and migration is still largely unknown. In our study, we observed that the FSCN1 expression rates were significantly higher in invasive ductal carcinoma, compared with both usual ductal hyperplasia and ductal carcinoma in situ. FSCN1 expression was significantly higher in cases of TNBC compared with the non-TNBC subtype. Overexpression of FSCN1 promoted TNBC cell migration and invasion. Epidermal growth factor induced the expression of FSCN1 through activation of MAPK, which subsequently promoted cell migration and invasion. A significant decrease in FSCN1 expression following the co-treatment of FSCN1 siRNA and Gefitinib, compared with the separate treatment of FSCN1 siRNA or Gefitinib. Furthermore, we found that there was a significant association between FSCN1 expression and poor relapse-free survival and overall survival. Therefore, we suggest that co-targeting epidermal growth factor receptor and FSCN1 dual biomarker may be used as a novel therapeutic strategy for TNBC.