Low pretreatment prognostic nutritional index predicts poor survival of urologic cancer : an observational meta-analysis

Background: The pretreatment prognostic nutritional index (PNI) has been reported to be a potential prognostic marker of urologic tumors in succession, but the evidence is not decisive. In this study, meta-analysis was performed to better elucidate the prognosis of pretreatment PNI in patients with urologic tumors. Methods: Data from PubMed, Embase, and Web of Science databases were extracted and integrated from the matching articles (until October 12, 2017). Pooled hazard ratio (HR) and 95% confidence interval (CI) were collected and calculated for PNI of overall survival (OS) by Stata 12.0. Twelve studies involving 6786 cases met the criteria for inclusion and provided available data to evaluate the prognostic value of PNI in urologic cancer. Results: The pooled HR reached 1.72 (95% CI: 1.48-2.00, P<0.001) of OS by applying the fixed effect model on account of low heterogeneity in urologic cancer (I2: 0; P=0.509, nine studies containing 4735 cases). Moreover, subgroup analyses indicated that the association between low PNI and worse OS in urologic tumors was stable despite variations in region, publication time, and cut-off value. Conclusion: Low pretreatment PNI could serve as an adverse predictor of prognosis in urologic cancer. It predicts poor survival of urologic cancer based on our research. Further prospective studies are necessary to verify the role of PNI in urologic cancer.