Overexpression of CXCR2 predicts poor prognosis in patients with colorectal cancer

// Jingkun Zhao 1, 2, 3, * , Baochi Ou 1, 2, * , Hao Feng 3 , Puxiongzhi Wang 1 , Shuai Yin 3 , Congcong Zhu 1, 2 , Shenjie Wang 1 , Chun Chen 1, 2 , Minhua Zheng 1 , Yaping Zong 1 , Jing Sun 1 , Aiguo Lu 1 1 Shanghai Minimally Invasive Surgery Center, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, PR China 2 Shanghai Institute of Digestive Surgery, Shanghai, PR China 3 Department of General, Visceral, Transplantation, and Vascular Thoracic Surgery, Hospital of University of LMU Munich, Munich, Germany * These authors contributed equally to this work Correspondence to: Aiguo Lu, email: luaiguo1965@163.com Jing Sun, email: jingsun1982@sina.cn Keywords: colorectal cancer, CXCR2, prognosis, CXCL5 Received: October 19, 2016      Accepted: February 28, 2017      Published: March 10, 2017 ABSTRACT Colorectal cancer is a heterogeneous disease. Although many risk factors are used to predict colorectal cancer patients’ prognosis after surgical resection, new prognostic factors are still needed to be defined to promote predictive efficacy of prognosis and further guide therapies. Herein, we identified the prognostic significance of CXCR2 in colorectal cancer patients. We retrospectively analysed 134 patients with colorectal cancer who underwent minimally invasive surgery between 2010 and 2011. The overall cohort was divided into a training set ( n = 78) and a validation set ( n = 56). We detected CXCR2 expression using immunohistochemical staining and defined the cut-off value using X-tile program. Next, we analysed the association between CXCR2 expression and clinicopathologic features in training and validation sets. High expression of CXCR2 was associated with Dukes stage ( P = 0.018), tumor invasion ( P = 0.018) and liver metastasis ( P = 0.047). Multivariate COX regression analyses confirmed that high CXCR2 level was an independent prognostic risk factor for both overall survival and disease free survival. Kaplan-Meier survival analysis demonstrated that patients with high expression of CXCR2 had a poor overall survival and disease free survival even in low-risk group (I + II). This indicated that CXCR2 can help to refine individual risk stratification. In addition, we established Nomograms of all significant factors to predict 3- or 5-years overall survival and disease free survival. Moreover, we found the combination of CXCR2 and its ligand CXCL5 had more significant value in predicting the prognosis than single CXCR2 factor.