The outcome of patients with triple negative breast cancer: Evidence for a favorable ethnic subgroup? The Turkish Oncology Group experience

Abstract

e22158 Background: Triple negative breast cancer (TNBC) is generally considered as a poorer prognostic subgroup, with a propensity for earlier relapse and visceral involvement. The aim of this study is to evaluate the outcome of non-metastatic TNBC patients in a National registry setting and identify clinical and pathologic variables associated with survival. Methods: From a retrospective registry cohort of 296 TNBC patients treated and followed between 1993–2007, we identified 248 patients with early stage disease, with follow-up of at least 12 months. The prognostic impact of several clinical variables were evaluated by the Kaplan-Meier and Cox multivariate anayses. Results: Median age was 48. The majority of the patient group had invasive ductal carcinoma (n:204, 82.3%). Distribution by stage was as follows: stage 1: 49 (19.8%), st 2: 125 (50.4%), st 3: 69 (27.8%). Excluding 11 patients, all had received adjuvant chemotherapy. 5 year overall survival (OS) and disease-free survival (DFS) rates were 84±2.7 % and 69±3.3%, respectively. Median survival after initial recurrence was 20 months. Sites of relapse were as follows: lung: 26 (36.1%), liver:8 (11.1%), brain: 8 (11.1%), bone: 14 (19.4%), skin/lymphatic: 7 (9.7%). Univariate analysis revealed locally advanced disease (p:0.0001), larger tumor size (p:0.004), nodal positivity (p<0.00001), and extent of nodal involvement as significant factors for DFS; whereas, locally advanced disease (p:0.0099) and extent of nodal involvement (p:0.018) were identified as prognostic factors with an impact on OS. Multivariate analysis revealed locally advanced disease (HR: 3.3, p:0.02, 95% CI: 0.14–0.64) and extent of nodal involvement (HR:4.3, p:0.033, 95% CI: 0.059–0.88) as significant independent prognostic factors for DFS and OS, respectively. Conclusions: The outcome of patients with TNBC in this National registry cohort is comparable to other subsets with similar prognostic features and do not support the generally accepted notion that TNBC entails poor prognosis. It may be speculated that there may be inherent ethnic differences leading to distinctive tumor behaviour. Further translational research is required to identify molecular prognostic groups within the TN subset. No significant financial relationships to disclose.