Li D, et al. - Whether and how tumor size influences the prognosis for surgically treated patients with pancreatic ductal adenocarcinoma (PDAC) was investigated via a systematic review and meta-analysis. Researchers searched EMBASE and PUBMED to identify relevant studies published from January 2000 to June 2017. They used Review Manager 5.3 to pool data for meta-analysis. A total of 28 observational studies with 23,945 patients were included. According to findings, an independent factor for poor prognosis after surgical resection is PDAC size > 2 cm, as it was related to more aggressive tumor biology.