Outcomes of complete metastasectomy in metastatic renal cell carcinoma patients: The Canadian Kidney Cancer information system experience

Surgical resection of metastasis can be integrated in the management of metastatic renal cell carcinoma (mRCC) as it can contribute to delay disease progression and improve survival. This study assessed the impact of complete metastasectomy in mRCC patients using real-world pan-Canadian data. The Canadian Kidney Cancer information system (CKCis) database was used to select patients who were diagnosed with mRCC between January 2011 and April 2019. To minimize selection bias, each patient having received a complete metastasectomy was matched with up to 4 patients not treated with metastasectomy. Overall survival (OS) was calculated from the date of metastasectomy or selection, to death from any cause. A Cox proportional hazards model was used to assess the impact of the metastasectomy while adjusting for potential confounding variables. A total of 229 patients undergoing complete metastasectomy were matched with 803 patients not treated with metastasectomy. After matching, baseline characteristics were well balanced between groups. After 12 months, the proportion of patients that were still alive was 96.0% and 89.8% in the complete metastasectomy and its matched group, respectively; the 5-year OS were 63.2% and 51.4%, respectively. Multivariate analysis performed in the matched cohort revealed that patients who underwent complete metastasectomy had a lower risk of mortality compared to patients who did not undergo metastasectomy (hazard ratio: 0.41, 95% confidence interval:0.27–0.63). Our study found that patients who underwent complete metastasectomy have a longer overall survival and a longer time to initiation of targeted therapy compared to patients not receiving metastasectomy. These findings should support aggressive resection of metastasis in selected patients.