Comparing partial nephrectomy and percutaneous ablation for treatment of renal masses

Radical nephrectomy has been the standard of care for management of kidney cancer for nearly 40 years. Since that time, partial nephrectomy (PN) has emerged as an effective option that provides comparable oncologic control for patients with small renal masses and provides the benefits of renal preservation in situations where this is imperative to avoid dialysis.

Over the past 10 to 15 years, ablative procedures, including percutaneous radiofrequency ablation (RFA) and percutaneous cryoablation, have joined the list of treatment options available for patients who are poor surgical candidates. As experience with these nephron-sparing procedures has grown, urologists have gradually expanded their use to include patients with normal renal function and larger renal masses.

Although cryoablation and RFA have traditionally been thought to provide inferior outcomes compared with surgical removal, current scientific literature lacks a large body of research data comparing cancer-related outcomes associated with these procedures. Because Mayo Clinic performs hundreds of these procedures on a yearly basis, Mayo researchers thus decided to evaluate their experience with management of cT1 renal masses and compare oncologic outcomes associated with PN, percutaneous RFA and percutaneous cryoablation.

Study design and results

Published in European Urology, the results of the Mayo study show near equivalent oncologic outcomes among patients treated with PN, percutaneous RFA and percutaneous cryoablation.

Mayo researchers used the Mayo Clinic Renal Tumor Registry to identify a total of 1,803 patients treated for primary renal masses between 2000 and 2011. Study subjects were divided into two groups: patients with tumors 4 cm or less (cT1a patients) and those with tumors 4 to 7 cm (cT1b patients).

In the cT1a cohort, 1,057 patients received PN, 180 received RFA and 187 received cryoablation. Local recurrence-free survival (p=.49) was similar among the three treatment groups, while metastases-free survival was significantly better for patients who received PN (p=0.005) and cryoablation (p=0.021) when compared with patients who received RFA.

In the cT1b cohort, 326 patients underwent PN, 53 patients received cryoablation, and the 8 patients who received RFA were excluded. In this cohort, local recurrence-free survival (p=0.81) and metastases-free survival (p=0.45) were similar between PN and cryoablation.

In both the cT1a and cT1b groups, patients who received PN were significantly younger, had lower Charlson scores and superior overall survival (p<0.001 for all). Mayo researchers note that study limitations include retrospective review and selection bias, but they are hopeful that these findings encourage further investigation of these treatment modalities among patients with early-stage kidney cancer.

For more information

Thompson RH, et al. Comparison of partial nephrectomy and percutaneous ablation for cT1 renal masses. European Urology. 2014.