Triple-negative Breast Cancer: What Is Known About It?

Lisa L. Ferguson, DNP, RN, WHNP-BC; Britne Curran, MSN, RN, WHNP-BC; Mary Martinez, MSN, RN, WHNP-BC; Peggy Mancuso, PhD, RN, CNM


Clin J Oncol Nurs. 2014;18(1) 

In This Article


Breast cancer is divided into subgroups and distinguished by tumor appearance based on a histologic classification system (de Ruijter, Veeck, J. de Hoon, van Engeland, & Tjan-Heijnen, 2011). The histology of breast cancer includes subtypes and grading based on tumor size, lymph node involvement, and distant metastasis occurrence (de Ruijter et al., 2011; Edge et al., 2010). Important characteristics, such as stage, histopathology, grade, and receptor status, help identify the type of breast cancer among women. These characteristics are used by clinicians to determine what treatment would be most effective (Francescutti et al., 2011).

TNBC is defined pathologically by the lack of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) (Masuda et al., 2011). According to Telli and Ford (2010), the majority of TNBCs have similarity in their basal-like pattern of gene expression, characterized by a high appearance of multiplying genes and basal cytokeratins. Subsequently, TNBC is typically more aggressive biologically when compared to other types of breast cancer, making it unresponsive to endocrine and monoclonal antibody therapies (Colfry, Humphries, & Fuhrman, 2011; Reeder-Hayes, Carey, & Sikov, 2010).

The aggressive nature of TNBC exhibits large tumors of elevated nuclear and histologic grades, with a high proliferative rate leading to poorer prognosis and increased recurrence rates (Reeder-Hayes et al., 2010). TNBC also displays rapid metastasis, spreading to distant sites, particularly the lungs and brain (Colfry et al., 2011). Breast cancers that are metastatic hormone receptor-positive usually cause late bone metastases, whereas TNBC is more likely to cause early visceral metastases (Hudis & Gianni, 2011).