Triple-negative breast cancer: An institutional analysis.

Objective: Triple-negative breast cancer (TNBC) is defined by the lack of expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER 2)/neu. It has been identified as an independent poor prognostic factor for survival. The aim of this study was to compare the clinico-pathological characteristics and treatment outcomes of patients with TNBC and non-TNBC.

Methods: We carried out an analysis of 706 patients with invasive breast cancer between January 2007 and December 2011 in whom information on the status of ER, PR, and HER2/neu were available.

Results: One hundred and fifty-five patients (21.9%) patients had TNBC. Patients with TNBC had a significantly lower median age [46.2 vs. 49.8 years; P = 0.005, 95% confidence interval (CI): 0.98 to 2.38] and a higher proportion of high-grade tumors as compared to the non-TNBC group (43 vs. 24%; P < 0.0001). After a median follow-up of 30 months, the three-year relapse-free survival (RFS) was significantly lower in the TNBC group (76 vs. 64%; log rank P = 0.002). Three-year overall survival (OS) was lower in the TNBC group but not statistically significant. Age <49 years, higher nodal stage, and larger tumor size (>5 cm) were associated with poor outcome.

Conclusions: TNBC is significantly associated with younger age and high-grade tumors and constitutes 21.9% of all breast cancers in our institute. Triple negativity was a significantly poor prognostic factor for RFS but not OS.