Login to Access Video or Poster Abstract: MP100-20
Sources of Funding: None

Introduction

Ablative treatments achieve good oncological outcome for renal parenchymal tumors 3 centimeters (cm) or smaller. Larger renal malignancies are increasingly being treated with ablation. This comparative study determines the survival following ablation in these large renal masses.

Methods

Patients undergoing cryotherapy or thermal ablation (Procedure codes 13, 15, or 23) for renal tumors were identified from the Surveillance, Epidemiology, and End Result (SEER) Database from 1998-2013. Exclusion criteria included T stage not recorded, more than one primary malignancy, metastatic disease, or node positive disease. Demographics, stage, and overall (OS) and cancer specific survival (CSS) were analyzed. T1a tumors were compared to T1b or T2 tumors. Tumors 3 cm or less were compared to greater than 3 cm.

Results

A total of 4,886 patients were identified, and 2,340 patients met inclusion criteria. The mean age was 66.5 years, 1,943 were white, 243 were black, and 1,419 were male. The stage distribution included T1a (n=2159), T1b (n=172), and T2 (n=9). 1,186 tumors were right-sided, 1,149 were left-sided, and the remaining were bilateral or not specified. 2,326 patients had the size recorded. 1,637 patients had 3 cm or smaller tumors and 689 tumors were larger than 3 cm. The OS in T1a tumors was 84.4% at 5 years and 69.2% at 9 years. In individuals with T1b tumors, OS was 62% at 5 years and 38% at 9 years. The T2 tumors had an OS of 64.8% at 57 months. The 5 year CSS was 97.4% in the whole group, 97.9% in T1a, and 97.4% in the T1b group. The corresponding 9 year CSS was 96.9, 97.5, and 96.9%. Comparative CSS in patients with T1a tumors was 98% at 5 years and 97.5% at 9 years. In T1b or greater tumors, the 5 and 9 year survival was 90.2%. All patients that survived beyond 5 years were alive at 9 years of follow-up. On analysis by size, tumors 3 cm or less had a 98.4 5-yr and a 98.2 9-yr CSS and tumors that were greater than 3 cm had 95% 5-yr and a 93.9 9-yr survival. On univariate analysis, both T1a tumors and tumors smaller than 3 cm had significantly better survival (p=0.001).

Conclusions

Ablative therapies for small renal masses can achieve excellent CSS at 97% at 9 years. This study demonstrates that reasonable CSS can be achieved in masses larger than 3 cm and patients with T1b or larger tumors. Further studies are required to address the role of ablative therapies for larger renal masses.

Funding

None