Potential candidate biomarkers for heterogeneity in triple-negative breast cancer (TNBC)

Triple-negative breast cancer (TNBC) exhibits a distinct pattern of recurrence characterized by a rapidly rising rate in the first 2 years with a peak at 2-3 years, followed by a decline over the next 5 years. However, some TNBC patients exhibit indolent clinical behavior. The aim of this study was to investigate clinical characteristics and outcomes of metastatic TNBCs. In addition, we were to find out the marker which could divide TNBCs into a few subgroups according to different clinical features. We retrospectively analyzed the clinicopathologic characteristics and outcomes of patients with metastatic TNBC who received palliative treatment between 1999 and 2007. The median relapse-free survival (RFS) and overall survival (OS) of 152 patients were 24 and 20 months, respectively. Divided TNBCs based on a RFS of 36 months, the patients with a RFS of a parts per thousand yen36 months had a better disease control rate (DCR), progression-free survival (PFS), and OS than those with a RFS of < 3 years. Cox-regression multivariate analysis for RFS and OS revealed EGFR positivity and a low BRCA1 score as an independent risk factor for OS. The patients with a RFS a parts per thousand yen 3 years had a significantly better DCR, PFS, and OS than patients who had a RFS < 3 years. BRCA1 and EGFR expression may be candidate determinants to distinguish RFS. A prospective clinical trial for different therapeutic strategies is needed for each subgroup.