International Multi-institutional Characterization of the Perioperative Morbidity of Metastasectomy for Renal Cell Carcinoma

Background: Surgical resection of metastatic renal cell carcinoma (mRCC) has been associated with better cancer-specific survival; however, high-quality data on its periop-erative morbidity are lacking. Existing population-based data are severely limited by reliance on billing claims to identify outcomes, which may overestimate events owing to a lack of code specificity.Objective: To study 30-d complications after metastasectomy for mRCC.Design, setting, and participants: The study involved a retrospective cohort of patients who underwent metastasectomy for mRCC between 2005 and 2020 at two high -volume centers. Outcome measurements and statistical analysis: We used generalized estimating equa-tions for a binary response to evaluate associations of features with 30-d complications classified according to Clavien-Dindo grade.Results and limitations: A total of 740 metastasectomies in 522 patients were identified, including 543 performed in the Mayo Clinic and 197 in UZ Leuven. Among the 740 metastasectomies, 193 (26%, 95% confidence interval [CI] 23-29%) had a 30-d complica-tion and 62 (8%, 95% CI 7-11%) had a major (Clavien-Dindo III-V) complication, including eight (1%) perioperative deaths. Age, body mass index, American Society of Anesthesiologists score, metastasectomy concurrent with nephrectomy, multiple sites of metastasis, pancreatic resection, and metastasis size were significantly associated with postoperative complications (all p < 0.05). Age, multiple sites of metastasis, and pancreatic resection were significantly associated with major (Clavien-Dindo III-V) com-plications (all p < 0.05). Limitations include the retrospective design and surgical selec-tion bias. Conclusions: In this multi-institutional series, fewer than 10% of metastasectomies for mRCC resulted in a major complication within 30 d of surgery, which is considerably lower than previously observed in population-based data. Favorable perioperative out-comes can be achieved with metastasectomy at high-volume centers in well-selected patients.