MYC overexpression with its prognostic and clinicopathological significance in breast cancer

// Jingkun Qu 1, * , Xixi Zhao 2, * , Jizhao Wang 1 , Xu Liu 1 , Yan Yan 1 , Lin Liu 1 , Hui Cai 1, 3 , Hangying Qu 4 , Ning Lu 4 , Yuchen Sun 5 , Feidi Wang 2 , Jiansheng Wang 1 and Jia Zhang 1 1 The Second Department of Thoracic Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061, P.R. China 2 Department of Oncology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710004, P.R. China 3 Department of Vascular Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061, P.R. China 4 Department of Oncological Surgery, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 712046, P.R. China 5 Department of Radiation Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710061, P.R. China * These authors have contributed equally to this work Correspondence to: Jiansheng Wang, email: wangjsh@mail.xjtu.edu.cn Jia Zhang, email: zhangjiaxjtu@xjtu.edu.cn Keywords: breast cancer, MYC, prognosis, clinicopathology, meta-analysis Received: July 21, 2017 Accepted: August 31, 2017 Published: October 05, 2017 ABSTRACT Background: Proto-oncogene MYC has been indicated to promote progression of many cancers. However, prognostic and clinicopathological significance of MYC in breast cancer need further evaluation. Methods: We searched EMBASE and PubMed databases to find useful studies. We analyzed relationships between high MYC expression and prognostic data/ clinicopathological features through hazard ratio (HR) and odds ratio (OR). Each statistical test was two-sided. Results: There were 29 studies (36 cohorts) with 12621 patients enrolled in our study The MYC overexpression was associated with worse DFS/RFS (disease/relapse free survival) in 11 studies (16 cohorts) with 5390 patients, and OS (overall survival) of 7 studies (8 cohorts) with 2672 patients. Subgroup analysis according to ethnicity/technique/data source displayed that MYC overexpression was associated with poor DFS/RFS in FISH, other technique, all data source and Asian/Non-Asian subgroup, and worse OS in all subgroups. In addition, MYC overexpression was related to large tumor size, high histologic grade, lymph node metastasis, negative hormone receptors and positive Ki67 expression. Conclusions: Our results showed that MYC overexpression was associated with worse prognosis and high risk of breast cancer, especially in patients with negative hormone receptors, which highlighted the potential of MYC as a significant prognostic biomarker of breast cancer.