Renal function and survival following treatment for cT1N0 renal cell carcinoma in a veteran population.

Abstract

642 Background: Radical nephrectomy (RN), nephron sparing surgery (NSS) and thermal ablation (TA) are associated with similar oncologic control for early-stage renal cell carcinoma (RCC). However, the potential protective role of nephron sparing treatments on renal function and its impact on non-cancer related mortality remains undetermined. Methods: We employed the national Veterans Affairs Corporate Data Warehouse (CDW) to identify patients diagnosed with cT1N0 RCC between 2000-2018. Laboratory and diagnosis data were used to calculate creatinine clearance and Charlson comorbidity score. Chronic kidney disease (CKD) was defined as creatinine clearance < 60 milliliters per minute. Kaplan-Meier analysis and multivariable Cox regression analysis were used to evaluate overall survival. Results: Overall, there were 8279 Veterans with cT1N0M0 renal cell carcinoma diagnosed between 2000-2018 who received either RN (2946, 36%), NSS (4846, 59%) or TA (487, 6%). Median follow up time was 8 years (90% CI 2-15 years). Patients receiving RN were older than those receiving NSS (median age 64.0 vs 62.6 years, p<0.01) but younger than those receiving TA (median age 67.9 years, p<0.01). Patients receiving RN and TA had more comorbidities than patients receiving NSS (mean Charlson scores 0.76 vs. 1.00 vs. 0.66, p<0.01. More patients among the RN group had CKD before RCC diagnosis than the NSS and TA groups (10% vs. 6% vs. 7%, p<0.01). Among the subset of patients without CKD before treatment, 17% of RN, 8% of NSS, and 11% of TA developed CKD at least 1 year after treatment, (p <0.01). Median OS was 11.5 years with RN, 14.2 years with NSS, and 10.3 years with TA. On multivariable analysis considering age, comorbidities, CKD, race, and year of treatment, compared to RN, NSS was associated with better OS (HR 0.75, p<0.01) with a trend to improved survival with TA (HR 0.88, p=0.08). Conclusions: NSS or TA are associated with less post-operative renal dysfunction than RN in patients treated for cT1N0 RCC in the VAHCS. NSS is associated with improved OS compared to RN. Further studies are warranted to assess the impact of renal dysfunction in this population in relation to oncologic and survival outcomes.