Pre-treatment prognostic nutritional index may serve as a potential biomarker in urinary cancers: a systematic review and meta-analysis

BACKGROUND: To investigate the potential prognostic role of pre-treatment prognostic nutritional index (PNI) in urinary cancers. METHODS: Relevant articles were searched comprehensively from PubMed, Embase and Web of Science, up to November 2018. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted to evaluate their associations. RESULT: A total of 12 related articles including 6561 patients were ultimately enrolled. Our results indicated that a relatively lower level of pre-treatment PNI was associated with decreased OS, CSS/DSS and DFS/RFS/PFS (pooled HR = 1.68, 95% CI 1.45–1.95; pooled HR = 1.57, 95% CI 1.33–1.86; pooled HR = 1.75, 95% CI 1.53–1.99, respectively). Subsequent stratified analysis by cancer type for OS showed that PNI could also be a predictor no matter in renal cell cancer (RCC) or bladder cancer (BC) (pooled HR = 1.65, 95% CI 1.37–1.97 and pooled HR = 1.67, 95% CI 1.20–2.33). Similar results could be found in DFS/RFS/PFS (RCC: HR = 1.81, 95% CI 1.54–2.13 and BC: HR = 1.68, 95% CI 1.32–2.12) and in CSS/DSS (RCC: HR = 1.50, 95% CI 1.23–1.82 and upper tract urothelial carcinoma: HR = 1.61, 95% CI 1.13–2.28). As for the treatment subgroup, a relatively lower level of PNI could also be a positive predictor for OS (surgery: HR = 1.64, 95% CI 1.40–1.93; target therapy: HR = 1.88, 95% CI 1.34–2.63) and DFS/RFS/PFS (surgery: HR = 1.69, 95% CI 1.47–1.95; target therapy: HR = 2.14, 95% CI 1.50–3.05). CONCLUSION: The outcomes of us shed light on that elevated pre-treatment PNI was positively associated with OS, CSS/DSS and DFS/RFS/PFS, indicating that it could be an independent prognostic factor in urinary cancers.