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

Abstract

Introduction and Objective:

African American (AA) race has been identified to have a higher incidence of chronic kidney disease (CKD) and worse renal cancer survival compared with Caucasian Americans (CA), irrespective of tumor size, pathologic type, and surgical procedure. We aimed to compare the outcomes between CA and AA patients undergoing minimally invasive partial nephrectomy (PN) at our high-volume center.

Materials and Methods:

We queried our PN data repository from 2007 to 2017. We identified 981 cases of PN (robotic n = 943 and laparoscopic n = 38), of which there were 852 CA and 129 AA patients. We compared age, sex, body mass index (BMI), operative time, estimated blood loss (EBL), nephrometry score, tumor size, pre- and postoperative estimated glomerular filtration rate (eGFR), length of stay, Charlson Comorbidity Index (CCI), tumor characteristics, and 30-day complication rate. We then estimated the overall survival and disease-specific survival.

Results:

Age, BMI, operative time, EBL, nephrometry score, tumor size, CCI, length of stay, and sex were not statistically different. The mean preoperative eGFR was higher in the AA cohort (91.4 mL/min/1.73 m² vs 86.1 mL/min/1.73 m², p = 0.007); however, at 1 year, there was no mean difference (76.8 mL/min/1.73 m² vs 74.5 mL/min/1.73 m², p = 0.428). There was a higher percentage of Fuhrman Grade 3/4 in the AA cohort (33.3% vs 22.5%, p = 0.044). The AA cohort had a 2.66 × 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 30-day complications (p = 0.330). The median follow-up was 43.2 months. By using Kaplan–Meier curves, there was no observed difference in overall survival (p = 0.752) or disease-free survival (p = 0.403).

Conclusions:

Our cohort of AA and CA patients with intermediate follow-up showed no worse outcomes for CKD or survival when undergoing laparoscopic or robotic PN. For low-stage renal cancer, there was no difference in overall survival and disease-free survival at a median follow-up of 43.2 months among AA patients, despite having higher grade tumors and a higher percentage of unclassified RCC. Our cohort of AA patients did have a higher incidence of papillary RCC. The equivalent overall survival and disease-free 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.