Prognostic value of prognostic nutritional index in nasopharyngeal carcinoma: A meta-analysis containing 4511 patients

Objectives: The prognostic nutritional index (PNI) is an index reflecting the nutritional and inflammatory status of patients and is explored for prognosis in nasopharyngeal carcinoma (NPC). However, the data are conflicting. In the current study, a meta-analysis was performed to comprehensively clarify the association between PNI and prognosis of NPC. Materials and methods: PubMed, Web of Science, the Cochrane library, China National Knowledge Infrastructure (CNKI), and Wanfang database were searched up to July 25, 2020. Hazard ratio (HR) and with 95% confidence interval (CI) were calculated to assess the impact of PNI on the survival outcomes of patients with NPC. Results: A total of 10 studies containing with 4511 patients were identified. The pooled results showed that NPC patients with a low PNI would have a worse overall survival (OS) (HR = 1.89, 95%CI = 1.59-2.25, p < 0.001), distant metastasis-free survival (DMFS) (HR = 2.01. 95%CI = 1.66-2.43, p < 0.001), progression-free survival (PFS) (HR = 1.59, 95%CI = 1.32-1.91, p < 0.001), and locoregional recurrence-free survival (LRRFS) (HR = 1.51, 95%CI = 1.04-2.21, p = 0.032). Subgroup analysis showed that the low PNI was still a significant prognostic factor for OS and DMFS. Conclusions: Our meta-analysis demonstrated that a low PNI was significantly correlated to poor OS, DMFS, PFS, and LRRFS in NPC. Therefore, we suggest PNI applied as an indicator for prediction of the short- and long- term survival outcomes in patients with NPC.