Prognostic significance of positive peritoneal cytology in resectable pancreatic cancer: a systemic review and meta-analysis

// Feng Cao 1, * , Jia Li 1, * , Ang Li 1 , Fei Li 1 1 Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, PR China * These authors contributed equally to this work Correspondence to: Fei Li, email: feili36@ccmu.edu.cn Keywords: pancreatic cancer, surgery, cytology, overall survival, meta-analysis Received: September 20, 2016 Accepted: January 10, 2017 Published: January 19, 2017 ABSTRACT Although peritoneal cytology has been used to determine pancreatic cancer staging for more than three decades, its prognostic significance in potentially resectable pancreatic cancer is inconclusive. We therefore conducted this meta-analysis to investigate the impact of peritoneal cytology status on the clinicopathological features and survival outcomes in potentially resectable pancreatic cancer. Ten studies were identified for this meta-analysis after searching the PubMed, Web of Science and China National Knowledge Infrastructure (CNKI) electronic databases. Our results showed that positive peritoneal cytology was associated with tumor size (OR 11.65, P = 0.001), tumor location (OR 0.37, P = 0.000), serosal invasion (OR 3.89, P = 0.000), portal vein invasion (OR 1.82, P = 0.016), lymph vessel invasion (OR 2.71, P = 0.026), T stage (OR 2.65, P = 0.037) and N stage (OR 2.34, P = 0.001) in resectable pancreatic cancer. Patients with positive peritoneal cytology demonstrated poor overall survival (OS; HR 3.18, P = 0.000) and disease-free survival (DFS; HR 2.88, P = 0.000) times. Based on our meta-analysis, we conclude that positive peritoneal cytology is an indicator of advanced stage pancreatic cancer with a poor prognosis; hence, radical resection should not be performed on these patients.