The study investigated whether a replacement of neutrophil count and platelet count by neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) within the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model would improve its prognostic accuracy.
This retrospective analysis included consecutive patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors. The IMDC and Modified-IMDC models were compared using: concordance index (CI), bias-corrected concordance index (BCCI), calibration plots, the Grønnesby and Borgan test, Bayesian Information Criterion (BIC), generalized R2, Integrated Discrimination Improvement (IDI), and continuous Net Reclassification Index (cNRI) for individual risk factors and the three risk groups.
Three hundred and twenty one patients were eligible for analyses. The Modified-IMDC model with NLR value of 3.6 and PLR value of 157 was selected for comparison with the IMDC model. Both models were well calibrated. All other measures favoured the Modified-IMDC model over the IMDC model (CI: .706 versus .677; BCCI: .699 versus .671; BIC: 2176.2 versus 2190.7; generalized R2: .238 versus .202, IDI: .044, cNRI: .279 for individual risk factors, and CI: .669 versus .641; BCCI: .669 versus .641; BIC: 2183.2 versus 2198.1; generalized R2: .163 versus .123, IDI: .045, cNRI: .165 for the three risk groups).
Incorporation of NLR and PLR in place of neutrophil count and platelet count improved prognostic accuracy of the IMDC model. These findings require external validation before introducing into clinical practice.
Cancer research and treatment : official journal of Korean Cancer Association. 2017 Mar 03 [Epub ahead of print]
Pawel Chrom, Rafal Stec, Lubomir Bodnar, Cezary Szczylik
Department of Oncology, Military Institute of Medicine, Warsaw, Poland.