No association between triple-negative breast cancer and prognosis of patients receiving breast-conserving treatment

The role of triple-negative breast cancer (TNBC) in breast-conserving treatment is controversial. The present study aimed at evaluating the prognosis of patients with TNBC following breast-conserving treatment (BCT) within 5 years. The present study investigated a cohort of 757 patients with early stage breast cancer, diagnosed and treated with BCT between January 2002 and March 2010 at Tianjin Medical University Cancer Institute and Hospital. The patients were divided into three groups according to receptor expression: Estrogen receptor (ER) or progesterone receptor (PR)-positive; epidermal growth factor receptor 2 (HER2)-enriched: ER and PR negative but HER2-positive; TNBC: ER, PR and HER2 receptor-negative. The primary endpoint was recurrence or mortality within 5 years after breast cancer diagnosis. Multivariable Cox analysis was used to determine the risk of locoregional relapse, distant metastases, total relapse and mortality associated with the intrinsic subtypes. Of the 757 patients with status of all receptors available, 541 (71.5%) were luminal, 66 (8.7%) were HER2-enriched and 150 (19.8%) were TNBC. Patients with TNBC were more likely to have histological grade III tumors (27.3%) compared with luminal (8.3%) and HER2-enriched (16.7%) subtypes (P<0.001). Within 5 years, locoregional recurrence rate was 2.4, 7.6 and 7.3% for luminal, HER2-enriched and TNBC, respectively (P=0.005). Mortality rate was 2.2, 9.1 and 4.7% for luminal, HER2-enriched and TNBC, respectively (P=0.007). There was no significant difference in rates of distant metastases (P=0.164) and total relapse (P=0.138). TNBC was not an independent prognostic predictor for women treated with BCT within 5 years after breast cancer diagnosis on multivariate analysis. Patients with TNBC were not at significantly increased 5-year risks of locoregional recurrence, distant metastasis, total relapse or mortality at so remain appropriate candidates for BCT.