Rising Serum Uric Acid Level Is Negatively Associated with Survival in Renal Cell Carcinoma

Aim and Background: To investigate the association of serum uric acid (SUA) levels along with statin use in Renal Cell Carcinoma (RCC), as statins may be associated with improved outcomes in RCC and SUA elevation is associated with increased risk of chronic kidney disease (CKD). Methods: Retrospective study of patients undergoing surgery for RCC with preoperative/postoperative SUA levels between 8/2005-8/2018. Analysis was carried out between patients with increased postoperative SUA vs. patients with decreased/stable postoperative SUA. Kaplan-Meier analysis (KMA) calculated overall survival (OS) and recurrence free survival (RFS). Multivariable analysis (MVA) was performed to identify factors associated with increased SUA levels and all-cause mortality. The prognostic significance of variables for OS and RFS was analyzed by cox regression analysis. Results: Decreased/stable SUA levels were noted in 675 (74.6%) and increased SUA levels were noted in 230 (25.4%). A higher proportion of patients with decreased/stable SUA levels took statins (27.9% vs. 18.3%, p = 0.0039). KMA demonstrated improved 5- and 10-year OS (89% vs. 47% and 65% vs. 9%, p < 0.001) and RFS (94% vs. 45% and 93% vs. 34%, p < 0.001), favoring patients with decreased/stable SUA levels. MVA revealed that statin use (Odds ratio (OR) 0.106, p < 0.001), dyslipidemia (OR 2.661, p = 0.004), stage III and IV disease compared to stage I (OR 1.887, p = 0.015 and 10.779, p < 0.001, respectively), and postoperative de novo CKD stage III (OR 5.952, p < 0.001) were predictors for increased postoperative SUA levels. MVA for all-cause mortality showed that increasing BMI (OR 1.085, p = 0.002), increasing ASA score (OR 1.578, p = 0.014), increased SUA levels (OR 4.698, p < 0.001), stage IV disease compared to stage I (OR 7.702, p < 0.001), radical nephrectomy (RN) compared to partial nephrectomy (PN) (OR 1.620, p = 0.019), and de novo CKD stage III (OR 7.068, p < 0.001) were significant factors. Cox proportional hazard analysis for OS revealed that increasing age (HR 1.017, p = 0.004), increasing BMI (Hazard Ratio (HR) 1.099, p < 0.001), increasing SUA (HR 4.708, p < 0.001), stage III and IV compared to stage I (HR 1.537, p = 0.013 and 3.299, p < 0.001), RN vs. PN (HR 1.497, p = 0.029), and de novo CKD stage III (HR 1.684, p < 0.001) were significant factors. Cox proportional hazard analysis for RFS demonstrated that increasing ASA score (HR 1.239, p < 0.001, increasing SUA (HR 9.782, p < 0.001), and stage II, III, and IV disease compared to stage I (HR 2.497, p < 0.001 and 3.195, p < 0.001 and 6.911, p < 0.001) were significant factors. Conclusions: Increasing SUA was associated with poorer outcomes. Decreased SUA levels were associated with statin intake and lower stage disease as well as lack of progression to CKD and anemia. Further investigation is requisite.