Trans-arterial embolization of renal cell carcinoma: a systematic review and meta-analysis

Purpose: To evaluate if trans-arterial embolization (TAE) of the primary tumor in patients with renal cell carcinoma (RCC) improves symptomatology such as pain and hematuria or oncologic outcomes such as progression-free survival (PFS) and overall survival (OS). Materials and methods: The systematic review search included PubMed, Ovid/MEDLINE, and Embase for full-text English articles including randomized and non-randomized prospective trials as well as prospective and retrospective case series. To be included, prospective trials needed ≥ 25 patients in each arm while case series and retrospective chart reviews required at least two patients. Evaluated outcomes included PFS, OS, change in tumor size, improvements in pain, improvements in hematuria, and adverse events (AEs). Results: 1327 articles were retrieved and screened. Nine studies met inclusion criteria (retrospective case series, n = 8; non-randomized prospective trial, n = 1) which included 237 patients (M = 156 (65.8%); F = 56 (23.6%); gender unreported = 25 (10.5%); mean age: 69.4 (range: 38–87)) with a mean tumor diameter of 9.3 cm (5.2–10.5). When reported, the TNM stages were stage I (n = 10), II (n = 18), III (n = 36), and IV (n = 121). 60 patients were treated for pain and hematuria. After TAE, pain improved in 59 patients (98.3%) and hematuria improved in 57 patients (95%). A meta-analysis for improvements in pain and hematuria demonstrated an event rate of pain improvement of 0.952 (0.788–0.990; p < 0.001) and an event rate for hematuria improvement of 0.923 (0.809–0.971; p < 0.001). Median OS ranged from 1 to 39 months but only one study reported PFS (10.5 months). Only one study demonstrated a statistically significant improvement in OS with TAE when compared with patients that did not undergo TAE (p = 0.02). A reduction in tumor size was only achieved in 17 patients (17/49; 34.7%) limiting evaluation. AEs included fever (n = 115/237; 48.5%), flank pain (n = 72/237; 30.4%), nausea (n = 58/237; 24.5%), hematuria (n = 12/237; 5.1%), hypertension (n = 12/237; 5.1%), reduced GFR (n = 6/237; 2.5%), hematoma (n = 6/237,2.5%), and ileus (n = 3/237; 1.3%). Conclusion: TAE monotherapy of the primary tumor in patients with RCC improves symptomatology such as pain and hematuria with an acceptable safety profile.