Systemic immune-inflammation index predicts the clinical outcome in patients with metastatic renal cell cancer treated with sunitinib

BACKGROUND In this retrospective analysis, we explored the prognostic and predictive value of the systemic immune-inflammation index (SII), based on lymphocyte, neutrophil, and platelet counts, at baseline and changes at week 6 during first-line sunitinib in patients with metastatic renal cell cancer (RCC). RESULTS Patients were stratified into high SII (≥ 730) and low SII (< 730) groups. SII was associated with objective response, p < 0.0001. The median PFS was 6.3 months (95% CI 5.5-8.9) in patients with SII ≥ 730 and 18.7 months (95% CI 14.7-22.8) in those with SII < 730, p < 0.0001. The median OS was 43.6 months (95% CI 35.3-52.1) in patients with SII < 730, and 13.5 months (95% CI 9.8-18.5) in those with SII ≥ 730, p < 0.0001. In multivariate analysis, performance status, IMDC score and SII were able to predict OS (HR = 3.29, HR = 1.71 and HR = 1.79, respectively). MATERIALS AND METHODS We included 335 consecutive RCC patients treated with first-line sunitinib. The X-tile 3.6.1 software (Yale University, New Haven, CT) was used for bioinformatic analysis of the data to determine the cutoff value of SII. Progression-free survival (PFS), overall survival (OS) and their 95% confidence interval (95% CI) were estimated by Kaplan-Meier method and compared with logrank test. The impact of SII conversion at week 6 of treatment on PFS and OS was evaluated by Cox regression analyses. CONCLUSIONS The SII and its changes during treatment represent a powerful prognostic indicator of clinical outcome in patients with metastatic RCC.