Expression of Fascin and DNA Topoisomerase 2-Alpha in Breast Carcinoma: Correlation with Histological Subtypes and Other Prognostic Markers

Abstract

BACKGROUND/OBJECTIVES: Breast cancer is the most prevalent cancer in adult women. Currently, new therapies and protein determinations with prognostic value are under development. Fascin (encoded by the FSCN1 gene) is an actin-binding protein that is critical for the development of cytoplasmic projections that are essential for tumor invasion. DNA topoisomerase 2-alpha (TOP2A) is a nuclear protein crucial for ATP-dependent breakage, passage, and rejoining of double-stranded DNA and cell division. Both proteins are associated with higher proliferation rates and worse prognosis in breast cancer and together can provide comprehensive information on prognosis and treatment response. METHODS: We simultaneously assessed fascin expression and TOP2A/CEP17 DNA copy number ratios in various histological and molecular subtypes. Additionally, these markers were analyzed along with previously established diagnostic markers and other relevant clinical data. RESULTS: Our series included 265 patients, four of whom were male, and all of which were diagnosed with breast carcinoma. Of the 265 patients initially included, sufficient material for analysis was available for 175 cases, as some samples were excluded because of insufficient tissue quantity, poor preservation, or lack of hybridization in certain assays. Immunohistochemical (IHC) expression of fascin, both in its aggregated form and by category, showed no association with the TOP2A gene alteration ratio. Fascin expression was significantly associated with histological subtype (p < 0.001), molecular subtype (p < 0.001), hormone receptor (HR) (p < 0.001), BCL2 (p = 0.003), Ki67 (p = 0.002), and histological grade (p < 0.001). TOP2A was significantly associated with molecular subtype (p = 0.041), Ki67 (p = 0.048), and histological grade (p = 0.033). In our study, molecular subtype (p = 0.037) emerged as an independent variable for the complete histological response to neoadjuvant treatment. Multivariate analysis linked pathological stage (p = 0.002) and estrogen receptor (ER) expression (p = 0.004) to overall survival (OS) and disease-free survival (DFS). CONCLUSIONS: No statistical relationship was evident between fascin expression (IHC) and the TOP2A copy ratio. The results of this study suggested that the mechanisms of increased cell proliferation associated with alterations in fascin and TOP2A are independent.