Outcomes of Cytoreductive Nephrectomy for Patients with Metastatic Renal Cell Carcinoma: Real World Data from Canadian Centers

Background Treatment options for metastatic renal cell carcinoma (mRCC) include cytoreductive nephrectomy (CN) and systemic therapy (ST). Results from the CARMENA and SURTIME trials suggest that CN before ST may not be the optimal treatment strategy for mRCC. Objective To use real-world data to evaluate and compare outcomes for patients with mRCC who underwent CN before, after, or without ST to those patients who only received ST. Design, setting, and participants The Canadian Kidney Cancer information system (CKCis) database was used to identify patients diagnosed with mRCC between January 2011 and April 2020. Only patients with synchronous disease, treated within 12 mo from their initial RCC diagnosis, with International Metastatic Renal Cell Carcinoma Database Consortium intermediate/high risk, and confirmed RCC histology were included. Outcome measurements and statistical analysis Patients were classified into four groups according to the initial treatment received for mRCC. Inverse probability of treatment weighting using propensity scores was used to balance the treatment groups. Cox proportional hazards models were used to assess the impact of CN after adjusting for potential confounding variables in the weighted cohorts. Results and limitations A total of 788 patients were included in the study cohort. Of these 383 patients underwent CN before ST, 73 underwent CN after ST, 80 underwent CN only, and 252 patients received ST only. The median patient age was 63 yr and 73% of the cohort were men. In weighted analysis, the groups undergoing CN before ST (hazard ratio [HR] 0.65, 95% confidence interval [CI] 0.52–0.82) and CN after ST (HR 0.41, 95% CI 0.28–0.60) both had better survival compared to the ST only group. No survival benefit was observed for CN only compared to ST only, or for CN before ST compared to CN after ST. Conclusions We evaluated the association between different sequences of treatment with CN and survival in patients with mRCC using CKCis real world data. The results demonstrate that the selected patients who undergo CN, whether performed before or after ST, have an associated improvement in survival. Patient summary Two of the treatment options for metastatic kidney cancer are surgery and systemic therapy (chemotherapy or immunotherapy). We used data from the Canadian Kidney Cancer information system to determine whether there are differences in survival according to the sequencing of these treatments. Patients who had both surgery and systemic therapy, regardless of which treatment was first, had better survival than patients who only received systemic therapy.