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Int J Clin Exp Pathol 2012;5(8):806-813

Original Article
Phosphorylated mTOR expression correlates with poor outcome in early-stage triple
negative breast carcinomas

Shir-Hwa Ueng, Shin-Cheh Chen, Yu-Sun Chang, Swei Hsueh, Yung-Chang Lin, Hui-Ping Chien, Yun-Feng Lo, Shih-Che Shen, Chuen Hsueh

Department of Pathology, Chang Gung Memorial Hospital, Linko; Department of Surgery, Chang Gung Memorial Hospital, Taipei; Chang Gung
Molecular Medicine Research Center and Graduate Institute of Basic Medical Sciences; Department of Oncology, Chang Gung Memorial
Hospital, Linko; Department of Pathology, Chang Gung Memorial Hospital, Keelong, Chang Gung University College of Medicine, Taoyuan,

Received August 13, 2012; Accepted September 7, 2012; Epub October 1, 2012; Published October 15, 2012

Abstract: The mammalian target of rapamycin (mTOR) plays an important role in cell growth, proliferation, and metabolism. Some studies
have associated phosphorylated mTOR (p-mTOR) expression with worse outcome in breast cancers. However, the significance of p-mTOR
expression specifically in triple negative breast carcinoma (TNBC) is unknown. In this study, p-mTOR expression was evaluated by
immunohistochemistry in 172 TNBCs and the result was correlated with clinicopathologic variables and disease outcome. The majority of
tumors (72.1%) were p-mTOR positive; p-mTOR expression did not correlate with age, tumor size, grade, lymph node status, or tumor stage. In
patients at stage 1 and 2 disease, those with p-mTOR expression had significantly worse overall as well as recurrence-free survival compared
to those without p-mTOR expression. p-mTOR expression appears to be an adverse prognostic indicator in early-stage TNBCs. The
assessment of p-mTOR expression in these tumors may also help to stratify patients for future target therapy studies. (IJCEP1208010).

Keywords: Phosphorylated mammalian target of rapamycin (p-mTOR), triple negative, breast cancer

Address all correspondence to:
Dr. Chuen Hsueh, Department of Pathology, Chang Gung Memorial Hospital, 5 Fu-Hsing Street, Kwei-Shan, Taoyuan 333, Taiwan; Tel: +886-3-
3281200 ext. 2741; Fax: +886-3-3280147; E-mail: ch9211@adm.cgmh.org.tw