Differences in CRP and De Ritis ratio predictive abilities of cancer specific survival between ethnic groups.

Abstract

394 Background: Studies have discussed the prognostic use of C-reactive protein (CRP) and De Ritis ratio (AST/ALT or AAR) in the evaluation of renal malignant masses. Elevated pre-treatment CRP has been shown to be associated with non-cancer mortality. Additionally increased preoperative AAR has been found to be a prognostic factor for overall survival. With studies showing the ethnic disparities in mortality rate in certain underserved ethnic groups, there is a need for investigation into possible ethnic differences. Our aim is to evaluate the association between these elevated preoperative markers and all-cause mortality (ACM) and cancer specific mortality (CSM) among ethnic groups. Methods: Retrospective review of the International Marker Consortium for Renal Cancer (INMARC) was performed. Patients with renal malignancies who underwent partial or radical nephrectomy (PN, RN) were included. Patients were grouped according to ethnicity and African American (AA), White, Asian, and Hispanic ethnic groups were selected for descriptive, survival and multivariable analysis of outcomes. A Cox-regression multivariable analysis (MVA) was performed for each group. The primary outcome was overall survival and cancer specific survival from time of surgery to last follow-up, which was evaluated using Kaplan-Meyer Analysis (KMA). Results: A total of 4,810 patients were analyzed (627 AA, 2,344 White, 462 Hispanic, 1,094 Asian). Preoperative CRP and AAR were considered elevated if above 5 mg/L and 1.26, respectively. Descriptive analysis showed significant differences in age, diabetes mellitus status, hypertension status, tumor size, surgery type (PN vs. RN), preoperative CRP, preoperative AAR, ACM and CSM between ethnicities (p-value <0.001). MVA revealed elevated CRP to be predictive of ACM in AA (p<0.001, HR 2.830, 95% CI [1.728, 4.635]) and White (p<0.001, HR 2.933, 95% CI [2.272, 3.785]) patients. Elevated AAR was only predictive for all ACM in Asian (p=0.004, HR 2.546, 95% CI [1.358, 4.775]) patients. MVA showed similar results for CSM with elevated CRP found to be a significant independent risk factor for CSM in AA (p<0.001, HR 7.006, 95% CI [2.649, 18.531]) and White (p<0.001, HR 3.391, 95% CI [2.403, 4.784]) patients while elevated AAR is a significant independent risk factor for all CSM in Asian (p=0.041, HR 2.374, 95% CI [1.034, 5.448]) patients. KMA revealed statistically significant impact of elevated CRP on ACM and CSM in AA, White, and Asian patients (p<0.001). It also showed a statistically significant effect of elevated AAR in Asian patients (p<0.001). Conclusions: CRP has broad utilities in prognostic abilities for non-Asian ethnic sub-cohorts. However, AAR has predictive abilities in Asian patients. These results show the importance of using different lab markers for preoperative assessment in renal masses and the need for further research in ethnic differences in clinical presentation.