Prognostic nutritional index as a prognostic factor for renal cell carcinoma: A systematic review and meta-analysis

Background Prognostic nutritional index (PNI) is a simple parameter which reflects patient's nutritional and inflammatory status and reported as a prognostic factor for renal cell carcinoma (RCC). Studies were included from database inception until February 2, 2022. The aim of this study is to evaluate prognostic value of PNI by meta-analysis of the diagnostic test accuracy in RCC. Methods and findings Studies were retrieved from PubMed, Cochrane, and EMBASE databases and assessed sensitivity, specificity, summary receiver operating characteristic curve (SROC) and area under curve (AUC). Totally, we identified 11 studies with a total of 7,296 patients were included to evaluate the prognostic value of PNI in RCC finally. They indicated a pooled sensitivity of 0.733 (95% CI, 0.651-0.802), specificity of 0.615 (95% CI, 0.528-0.695), diagnostic odds ratio (DOR) of 4.382 (95% CI, 3.148-6.101) and AUC of 0.72 (95% CI, 0.68-0.76). Heterogeneity was significant and univariate meta-regression revealed that metastasis and cut-off value of PNI might be the potential source of heterogeneity. Multivariate meta-regression analysis also demonstrated that metastasis might be the source of heterogeneity. Conclusions PNI demonstrated a good diagnostic accuracy as a prognostic factor for RCC and especially in case of metastatic RCC.