Effect of race-free estimated glomerular filtration rate equations (eGFR) on oncology clinical trial eligibility for Black patients.

Abstract

611 Background: Race is no longer recommended in estimated glomerular filtration rate (eGFR) equations. The resulting lower eGFR may positively impact black patients, such as with earlier nephrology referral. However, the impact of race-free equations on black oncology patients–a cohort more likely to experience inferior cancer outcomes and underrepresentation in clinical trials–has not been fully examined. Here, we analyze removal of race from eGFR in black patients with cancer, specifically with regards to clinical trial eligibility. Methods: Self-identified black patients undergoing nephrectomy at a referral center from 2009-2021 were identified. Patients with end-stage renal disease were excluded. Using preoperative creatinine, height, and weight, eGFR was calculated with the Chronic Kidney Disease Epidemiology Collaboration creatinine equation with and without race (CKD-EPI-WithRace; CKD-EPI-WithoutRace, respectively), and the Modification of Diet in Renal Disease equation with and without race (MDRD-WithRace; MDRD-WithoutRace, respectively). Distribution of patients and changes within CKD stages with different equations was considered. Theoretical exclusion at commonly observed clinical trial eGFR points was then simulated based on utilization of the race coefficient. Subgroup analysis was completed on patients with stage III-IV disease only. Results: 459 self-identified black patients that underwent nephrectomy at our institution were identified, 135 of which had stage III-IV disease. On average, eGFR decreased around 10-13ml/min/1.73m2 with removal of the race coefficient (Table). 13-22%, 6-12%, and 2-3% more black patients would fall under common clinical trial cutoffs of 60, 45, or 30ml/min cutoffs, respectively, depending on the equation used (Table). Subanalysis of stage III-IV patients only were similar. Conclusions: Race free renal function equations may inadvertently result in increased exclusion of black patients from clinical trials. [Table: see text]