Role of transforming growth factor-β1 in triple negative breast cancer patients

Background: We aimed to demonstrate the prognostic value of TGF-β1 in triple negative breast cancer (TNBC) and its association with clinicopathological characteristics of TNBC.

Materials and methods: A total of 180 women were randomly selected from non-metastatic invasive TNBC patients diagnosed at two hospitals between 2003 and 2012. Lmmunohistochemistry was performed to semi-quantify the expression of TGF-β1. Relationship between TGF-β1 expression and clinicopathological features was performed by Chi-square test. Univariate and multivariate survival analyses were performed to identify the prognostic role of TGF-β1 expression on survival outcomes.

Results: Of the 180 women included in this study, 67 (37.2%) patients expressed high level of TGF-β1. High expression of cytoplasmic TGF-β1 was correlated with higher histologic tumor grade (P < 0.001) and lymph node status (P < 0.001), and more axillary lymph node dissection (P = 0.029). High cytoplasmic TGF-β1 expression was associated with reduced disease-free survival (DFS) and overall survival (OS) by log-rank test (P_DFS<0.001, P_OS = 0.045). However, multivariate survival analyses showed that high TGF-β1 was marginally correlated with unfavorable DFS (hazard ratio (HR) 1.796, 95% CI 0.995-3.242, P = 0.052), while it was not significantly associated with OS (HR 0.747, 95% CI 0.367-1.522, P = 0.422).

Conclusions: This multi-centered retrospective study highlights the high expression of cytoplasmic TGF-β1 in TNBC is associated with higher histologic grade and lymph node status, more axillary lymph node dissection, as well as reduced DFS. Our observation that the prognostic role of TGF-β1 in TNBC suggests potential rationale for using therapeutic strategies based on targeting TGF-β1 in advanced tumors.