Racial Comparison of Patients Undergoing Minimally Invasive Partial Nephrectomy for Renal Masses at a Large Volume Tertiary Center.

Sands, Kenneth G; Bhatt, Rohit; Vetter, Joel; Paradis, Alethea; Chow, Alexander K; Bhayani, Sam; Figenshau, R Sherburne; Venkatesh, Ramakrishna J

Introduction African American (AA) race has been identified to have a higher incidence of chronic kidney disease (CKD) and worse renal cancer survival compared to Caucasian Americans (CA) irrespective of tumor size, pathological type, and surgical procedure. We compare the outcomes between CA and AA patients undergoing minimally invasive partial nephrectomy (PN) at our high-volume center. Methods We identified 942 robotic and 38 laparoscopic PN cases between 2007-2017 (852 CA and 129 AA). We compared demographics and perioperative outcomes. We then estimated the overall and disease-specific survival. Results Age, BMI, operative time, EBL, nephrometry score, tumor size, CCI, length of stay, and gender were not statistically different. The mean preoperative GFR was higher in the AA cohort (91.4mL/min/1.73m2 vs 86.1mL/min/1.73m2,p=0.007); however, at 1-year there was no mean difference (76.8mL/min/1.73m2 vs 74.5mL/min/1.73m2,p=0.428). There was a higher percentage of Fuhrman Grade 3/4 in AA (33.3% vs 22.5%,p=0.044). The AA cohort had a 2.66x higher incidence of papillary renal cell carcinoma (RCC) (34.9% vs 13.1%,p<0.001) and unclassified RCC (3.9% vs. 0.4%,p=0.001). There was no difference in tumor stage (p=0.260) or incidence of benign histology (15.3% vs 11.6%,p=0.278). There were no differences in thirty-day complications (p=0.330). There was no observed difference in overall survival (p=0.752) or disease-free survival (p=0.403) at 43.2 months. Conclusions For low stage renal cancer, there was no difference in CKD, overall and disease-free survival at a median follow up of 43.2 months, despite having higher grade tumors and a higher percentage of unclassified RCC in the AA cohort. AA had a higher incidence of papillary RCC. The equivalent survival could be due to the earlier discovery of lower stage renal masses incidentally identified on imaging studies performed equally for other reasons in both AA and CA patients.