Purpose: The prognostic utility of the prognostic nutritional index (PNI) in nasopharyngeal carcinoma (NPC) has never been systematically reviewed. Therefore, we performed this meta-analysis.
Methods: We performed comprehensive research via Embase, PubMed, Web of Science and the Cochrane Library. The pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were applied to explore the relationship between PNI and overall survival (OS), progression-free survival (PFS), locoregional failure-free survival (LRFFS), distant metastasis-free survival (DMFS) and clinical features. Both univariate analysis (UVA) and multivariate analysis (MVA) were used.
Results: A total of 8 eligible studies including 3631 patients were ultimately enrolled. A low PNI level was significantly associated with a shorter OS [(HR 2.06, P < 0.00001; UVA) and (HR 1.78, P < 0.00001; MVA)], PFS [(HR 2.27, P = 0.006; UVA) and (HR 1.45, P = 0.0003; MVA)] and DMFS [(HR 2.06, P < 0.00001; UVA) and (HR 2.04, P < 0.00001; MVA)]. However, only one study reported the LRFFS of NPC patients, and there was no significant difference [HR 1.68, P = 0.26]. Furthermore, female patients, higher tumor stage, a lower alanine transaminase (ALT) level and a lower white blood cell (WBC) level were associated with a lower PNI level.
Conclusion: Our meta-analysis indicated that NPC patients with a low PNI level had worse OS, PFS and DMFS, and a low PNI level was associated with female patients, higher tumor stage, a lower ALT level and a lower WBC level. These findings indicate that PNI is a promising prognostic biomarker.
Keywords: Meta-analysis; Nasopharyngeal carcinoma; Prognosis; Prognostic nutritional index.