BackgroundTargeted therapy combined with immunotherapy is the current first-line treatment for metastatic renal cell carcinoma (mRCC), but patients with tumor thrombus (TT) may suffer from lower limb edema or even sudden cardiac death, so the purpose of this study is to investigate the efficacy and safety of surgical treatment in patients with mRCC and TT and explore worse factors to affect the prognosis in this series of patients.Patients and methodsA total of 85 mRCC patients with TT who received cytoreductive nephrectomy and thrombectomy at our medical center from 2014 to 2023 are included. All patients received postoperative systemic therapy. Overall survival (OS) is defined as the time from surgery to death due to any reason or the last follow-up. Kaplan–Meier analysis was performed to evaluate OS and differences among groups were tested by log-rank. Multivariable Cox proportional hazards analysis was performed to ascertain independent relationships between clinicopathological factors and OS.ResultsThe median age of patients was 58 years old. Eleven patients (12.9%) had no symptoms, 39 patients (45.9%) had local symptoms, 15 patients (17.6%) had systemic symptoms, and 20 patients (23.5%) had both. Mayo grade of TT was 0, 1, 2, 3, and 4 for 12, 27, 31, 7, and 8 patients respectively. Fifty-five patients had lung metastasis, 23 had bone metastasis, 16 had liver metastasis, 13 had adrenal metastasis, and 9 had lymph node metastasis. Of all patients, 17 patients had multiple metastases. The median operation time is 289 min and the median intraoperative hemorrhage is 800 ml. Twenty-eight patients experienced postoperative complications, 8 of which were serious complications of modified Clavien grade III or higher. The median OS of all patients was 33 months and median follow up time was 26 months. In multivariate analysis, systemic symptom (p= 0.00753), pathological type (p= 0.0166), sarcomatous degeneration (p= 0.0334), and perirenal fat infiltration (p= 0.0202) are independent predictors of OS.ConclusionCytoreductive nephrectomy and thrombectomy is relatively safe and effective for patients with mRCC accompanied by TT. In this series of patients, the worse prognosis is associated with systemic symptoms, non-clear cell carcinoma, sarcomatous degeneration and perirenal fat infiltration.