ObjectiveTo evaluate the impact of age on cancer-specific mortality (CSM) and other-cause mortality (OCM) in patients undergoing radical nephrectomy with thrombectomy (RNTx) for renal cell carcinoma (RCC) with venous thrombus. Patients and MethodsWe retrospectively analyzed data from 196 patients who underwent RNTx for RCC with venous thrombus between 1990 and 2018 at a single tertiary referral center. Patients were grouped into three age groups: <60 years, 60-69 years, and ≥70 years. Clinical and pathological characteristics were compared. The cumulative incidence function (CIF) for CSM and OCM was calculated using the Aalen-Johansen estimator. We employed both sub-distributional hazard (SDH) and cause-specific hazard (CSH) models to evaluate the impact of age on mortality, using hazard ratios (HR) and 95% confidence intervals (CI) quantified associations. ResultsThe median follow-up was 40.5 months. During this time, 105 patients experienced disease progression, 125 had cancer-related deaths, and 155 deceased from any cause. Perioperative outcomes, including ICU admission, 90-day readmission, and 90-day mortality, showed no significant differences among age groups. The CIF for CSM revealed significant differences at 5-year (p = 0.032) but not at 10-years (p = 0.246). OCM increased with age, notably in the oldest group at 10 years (p = 0.045). Multivariable adjusted CSH and SDH models showed no significant differences in CSM among age groups. ConclusionAlthough the CIF for 5-year CSM and 10-year OCM were associated with increasing age, aging does not increase the hazard of CSM in both SDH and CSH models. Perioperative outcome does not differ between all age groups. For RCC with venous thrombus patients, older age alone is not absolute contraindication for surgical intervention. Micro-AbstractThis study assessed the impact of age on cancer-specific and other-cause mortality in patients undergoing radical nephrectomy with thrombectomy for renal cell carcinoma with venous thrombus. Although older age was associated with higher other-cause mortality at 10 years, age did not significantly affect cancer-specific mortality, suggesting that age should not be a contraindication for surgery in these patients. Perioperative outcomes were similar across all age groups.