Predictive value of the prognostic nutritional index in advanced non-small cell lung cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis

Purpose: The prognostic nutritional index (PNI), which is derived from the albumin concentration and absolute lymphocyte number, is an effective indicator of cancer patients' nutritional and immunological status. According to multiple studies, PNI was strongly linked to the prognosis of patients with non-small cell lung cancer (NSCLC). The predictive value of PNI for survival outcomes in NSCLC patients receiving immune checkpoint inhibitors (ICIs) is still in dispute at present. This meta-analysis is devoted to fill this information gap and investigate the predictive ability of PNI in NSCLC patients treated with ICIs. Methods: The PubMed, Embase, Cochrane Library databases, and conference proceedings were searched for eligible studies without language restriction. Overall survival (OS) and progressionfree survival (PFS) were included. The predictive value of PNI was estimated using hazard ratios and their 95% confidence intervals. Results: Thirteen relevant retrospective cohort studies were included and these studies included 1119 patients with stage III-IV NSCLC. Lower PNI status was found to be an independent risk factor for worse survival outcomes in patients with NSCLC (OS HR = 2.68; 95%CI: 1.76-4.06; P < 0.0001; PFS HR = 1.84; 95%CI: 1.39-2.42; P < 0.0001). According to the subgroup analysis, PNI was similarly connected to OS in most subgroups of NSCLC patients receiving ICIs, except for those receiving chemoimmunotherapy or first-line treatment, and those with a cut-off value < 45. Conclusion: Our findings indicated that lower PNI was associated with poorer prognosis in NSCLC patients undergoing ICI therapy. Further prospective research with bigger patient groups is required. Systematic Review Registration: International Prospective Register of Systematic Reviews (PROSPERO), identifier CRD42022327528.