Clinicopathologic and Prognostic Characteristics of Triple-Negative Breast Cancer

Background: Triple-negative breast cancer (estrogen receptor (ER)-, progesterone receptor (PR)-, and HER2-negative) is a rare subtype with a poor prognosis. However, the clinicopathologic and prognostic characteristics of triple-negative breast cancer remain undetermined. Materials and Methods: Immunohistochemical staining was adopted to examine the expressions of ER, PR, p53, C-erbB-2 (HER2), vascular endothelial growth factor (VEGF), and epidermal growth factor receptor (EGFR) protein in 116 samples of paraffin-embedded breast cancer tissues. Results: 22 triple-negative breast cancers were found among 116 informative cases (19%). The triple-negative phenotype significantly correlates with tumor size, histological grade, lymph node status, p53, and EGFR (p < 0.05), and not significantly with age, menopausal status, and VEGF protein. After a median follow-up period of 96 months (range: 32 - 123 months), 12 triple-negative breast cancer patients and 20 patients with non-triple-negative phenotype had distant relapse (p < 0.05). Survival analysis showed that triple-negative phenotype was inversely associated with overall survival (p < 0.05) but not significantly with disease-free survival (p = 0.2877). Multivariate Cox model analysis showed that tumor size, lymph node status, histological grade, and triple-negative phenotype provided independent significant predictive power. Conclusion: Triple-negative breast cancer phenotype has specific clinical and biological characteristics. Patients with triple-negative breast cancer have a poorer prognosis. So far, there is no conclusive effective treatment, which necessitates further studies.