Impact of the preoperative prognostic nutritional index on postoperative and survival outcomes in colorectal cancer patients who underwent primary tumor resection: a systematic review and meta-analysis

Purpose We aimed to explore whether the preoperative prognostic nutritional index (PNI) could be an indicator of prognostic outcomes in colorectal cancer (CRC) patients. Methods A systematic review and meta-analysis was conducted using the PubMed, Embase, and Web of Science databases. All original comparative studies published in English that were related to a high PNI versus a low PNI in CRC patients were included. Results A total of 10 studies involving 6372 patients were included in our meta-analysis. Our overall analysis indicated that the low-PNI group had a significantly reduced overall survival (OS) (HR = 1.87, 95% CI = 1.45–2.42, P