Predictors of Progression-Free Survival and Overall Survival in Metastatic Non-Clear Cell Renal Cell Carcinoma: A Single-Center Experience

BACKGROUND: Due to the infrequency of non-clear cell renal cell carcinoma (RCC), there is currently a paucity of high-quality literature to help guide the effective treatment of these tumors. Recently, biomarkers such as platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR), systemic immune inflammation (SII) index and C-reactive protein to albumin ratio (CAR) have been demonstrated to be closely related to poor prognosis of patients with RCC. The objective of this study was to evaluate these biomarkers for determining the progression-free survival (PFS) and overall survival (OS) in patients with metastatic non-clear cell cancer. METHODS: We retrospectively reviewed 31 cases diagnosed with metastatic non-clear cell RCC from January 2012 to December 2017. We assessed the prognostic value (OS and PFS) of pretreatment PLR, LMR, SII index and CAR based on multivariate analysis and Kaplan-Meier survival curve. RESULTS: Median time of OS and PFS were 15.5 months (95% confidence interval (CI): 13.7 - 15.2) and 10.9 months (95% CI: 8.9 - 12.8), respectively. The median PFS (0.001) and OS (P = 0.01) was shorter in patients with PLR > 171, LMR < 2.61. Moreover, median PFS but not OS was significantly lower in SII index > 883 (P = 0.064) and CAR > 0.11 (P = 0.229). Scan to surgery time (3.91 weeks, P = 0.001) was also significantly related to progression. CONCLUSIONS: Elevated pretreatment inflammatory biomarkers such as PLR, LMR, SII index and CAR are significant determinants of shorter PFS and OS (PLR and LMR only) in patients with metastatic non-clear cell RCC treated with cytoreductive nephrectomy.