Abstract
PURPOSE: To study the prognostic value of the prognostic nutritional index (PNI) in advanced cancers receiving programmed death-1/programmed death-ligand 1 (PD-1/L1) inhibitors. METHODS: Online electronic databases were comprehensively searched and available literature was retrieved. We extracted available data from included researches and pooled the hazard ratios (HRs) and 95% confidence intervals (CIs) to learn the prognostic value of PNI on overall survival (OS) or progression-free survival (PFS); and meanwhile calculated the relative risk (RR) with 95% CI to study the relationship between PNI and treatment efficacy (objective response rate [ORR] or disease control rate [DCR]) in late staged cancer receiving PD-1/L1 inhibitors. RESULTS: Nine studies were finally selected for this meta-analysis. We obtained data regarding PNI on OS from all nine studies, and the pooled HR was 2.31 (95% CI 1.81-2.94, p = 0.000), showing a correlation between low PNI and worse OS. Eight studies reported a relationship between PNI and PFS, and combined results revealed shorter PFS in patients with lower PNI, with an HR of 1.75 (95% CI 1.40-2.18, p = 0.000). Four studies explored the association between PNI and ORR and two studies explored the influence of PNI on DCR. An association between PNI and ORR (RR = 0.47, p = 0.003) was observed, while no association between PNI and DCR (RR = 0.49, p = 0.103) was observed by pooling these studies. CONCLUSION: In summary, this meta-analysis indicated that a lower PNI was significantly correlated with decreased OS and PFS and played adverse roles in ORR in advanced cancer patients receiving PD-1/L1 inhibitors. Therefore, PNI could be promising for predicting prognosis and treatment response in advanced malignancies treated with PD-1/L1 inhibitors.