Preoperative controlling nutritional status (CONUT) score as a novel immune-nutritional predictor of survival in non-metastatic clear cell renal cell carcinoma of ≤ 7 cm on preoperative imaging

Purpose: This study aimed at investigating the prognostic value of Preoperative controlling nutritional status (CONUT) score in non-metastatic clear-cell renal cell carcinoma of ≤ 7 cm on preoperative imaging. Methods: We retrospectively included 1046 among 1637 patients who underwent radical or partial nephrectomy for solid renal masses ≤ 7 cm (2005–2014) after excluding other pathology, conditions affecting CONUT score components, metastasis, regional lymphadenopathy, positive margin, and follow-up < 12 months. We defined high and low CONUT according to cut-off of (2). Multivariate Cox-regression analysis was used to predict factors affecting recurrence and survival. Kaplan–Meier curve was used for survival analysis. Results: The median age and follow-up were 56 years and 63 months, respectively. 41 patients had recurrence (3.9%). CONUT was a predictor for recurrence-free, cancer-specific, and overall survival (HR 3.09, P = 0.003 and HR 4.66, P = 0.004 and HR 2.81, P = 0.003, respectively). A higher CONUT was significantly associated with worse 5 years recurrence-free (88.2% vs. 97.1%), cancer-specific (96.2% vs. 98.8%) and overall (90.9% vs. 96.5%) survival (log-rank, P = < 0.001, P = 0.006 and P = < 0.001, respectively). Conclusions: The preoperative CONUT is an independent prognostic marker for survival after curative surgery for non-metastatic clear-cell renal cell carcinoma of ≤ 7 cm on preoperative imaging.