Prognostic role of tumour-associated macrophages and macrophage scavenger receptor 1 in prostate cancer: a systematic review and meta-analysis

// Jian Cao 1, 3, 4 , Jun Liu 2 , Ran Xu 1 , Xuan Zhu 1 , Xiaokun Zhao 1 and Bin-Zhi Qian 3 1 Department of Urology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China 2 Department of Urology, The Fifth Affiliated Hospital of Xinjiang Medical University, Wulumuqi, Xinjiang 830011, P.R. China 3 MRC Centre for Reproductive Health, Queen’s Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom 4 Current/Present address: Department of Urology, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, P.R. China Correspondence to: Bin-Zhi Qian, email: Binzhi.Qian@ed.ac.uk Keywords: prostate cancer, tumor-associated macrophages, macrophage scavenger receptor 1, prognosis, meta-analysis Received: September 24, 2016 Accepted: March 24, 2017 Published: June 27, 2017 ABSTRACT Recent studies suggested that the tumour associated macrophages may be associated with prostate cancer outcome. A meta-analysis was performed to evaluate the prognostic value of tumor associated macrophages and macrophage scavenger receptor 1, marker for a subset of macrophages, by pooled hazard ratio and 95% confidence intervals from qualified studies following a systemic search. The results indicate that higher infiltration of tumor associated macrophages predicts poor overall survival (HR=1.57, 95%CI: 1.15-1.98), but not biochemical recurrence (HR=1.01, 95%CI: 0.98-1.04) or recurrence-free survival (HR=1.03, 95%CI: 0.05-2.01). In contrast, elevated level of macrophage scavenger receptor 1 was significantly associated with better recurrence-free survival (HR=3.26, 95%CI: 1.22-5.29). Thus, our analysis confirmed the prognostic value of these markers in prostate cancer outcome. We also discussed potential causes of the controversies in the literature and future research directions.