Absence of transforming growth factor-beta type II receptor is associated with poorer prognosis in HER2-negative breast tumours.

BACKGROUND The clinical relevance of transforming growth factor-beta (TGF-beta)-signalling pathway in breast carcinomas (BCs) remained elusive. This study aimed to evaluate the prognostic value of TGF-beta1 and transforming growth factor-beta type II receptor (TGF-betaRII) expression levels in tumour cells and their association with the established biomarkers in BC. PATIENTS AND METHODS In 324 BC from patients with long-term follow-up, the TGF-beta1 and TGF-betaRII transcript and protein expression levels were assessed. RESULTS TGF-beta1 and TGF-betaRII down-expression was significantly associated with BC. Negative TGF-beta1 and TGF-betaRII protein status was associated with the development of distant metastasis (P = 0.003 and P = 0.029, respectively). In multivariate analysis, TGF-beta1-positive tumours were associated with increased disease-free survival (DFS) [hazard ratio (HR) = 0.489, P = 0.003]. TGF-betaRII positivity was an independent prognostic factor for DFS (HR = 0.439, P = 0.001) and overall survival (OS) (HR = 0.409, P = 0.003) in human epidermal growth factor receptor-2 (HER2)-negative patients. Absence of TGF-beta1 and TGF-betaRII proteins in breast tumour cells was significantly associated with metastasis development. CONCLUSIONS To the best of our knowledge, this is the first report indicating the relevance of HER2 status in discriminating TGF-betaRII as a prognostic marker for DFS and OS in human BC. These data indicate that TGF-betaRII protein analysis in tumour cells could be introduced in clinical practice as additional prognostic biomarker in HER2-negative BC.