The prognostic implications of redox protein expression in stage I-III triple-negative breast cancer.

Abstract

1035 Background: It is well known that increased reactive oxidative stress (ROS) in cancer cells correlates with poor prognosis and aggressiveness of tumor cells. The aim of this study is to investigate the expression of redox proteins in triple-negative, early breast cancer (TNBC) which shows aggressive phenotype among breast cancer and to demonstrate relationships between expression of ROS markers and clinical outcomes. Methods: Tissues from 135 cases of TNBC from curative surgery at Severance Hospital, Seoul, Korea, from December 2005 to January 2008 were analyzed. Immnunochemical (IHC) staining for redox proteins including thioredoxin reductase, glutathione S-transferase (GST) α, catalase, vitamin D-up-regulated protein 1 (VUDP), and manganese superoxide dismutase (MnSOD) was performed to evaluate the difference between clinicopathological parameters. The mono-carboxylate transporter 4 (MCT4) in stroma was done by IHC staining, too. Results: The median age of 135 TNBC patients was 48 (range 27-76). TNM staging were as follows; T1 (n=52, 38.5%), T2 (n=81, 60%), T3 (n=2, 1.5%), N0 (n=88, 65.2%), N1 (n=35, 25.9%), N2 (n=8, 5.9%), N3(n=4, 3.0%). Median follow up was 59 months (range 12-99). Samples were divided into high or low ROS expression level semi-quantitatively. The catalase high expressed group was tend to have lower N stage (p=0.016), lower tumor recurrence (p=0.02) as well as longer overall survival rates (p=0.05). Higher expression of MTC4 in stroma was strongly associated with higher MnSOD expression group analysis (p=0.015) and had significantly longer overall survival (p=0.032). Conclusions: This study shows the expression of ROS proteins could contribute defining aggressiveness of TNBC as well as the prognosis. Considering the lack of targeted molecules as well as molecular heterogeneity of TNBC, ROS markers may provide clues to clinical outcomes in TNBC.