Percutaneous ablation for small renal cell carcinoma (RCC) tumors in well-selected older patients may result in oncologic outcomes similar to those of radical nephrectomy, but with less long-term renal insufficiency and fewer perioperative complications, according to a new study.
In an observational study of 4310 patients aged 66 years or older who received treatment for renal tumors smaller than 4 cm (T1a RCC) from 2006 to 2011, the 5-year RCC-specific survival rate for patients who underwent percutaneous ablation (PA) and radical nephrectomy (RN) was 96% and 95%, respectively, a non-significant difference between treatment arms, Adam D. Talenfeld, MD, MS, of Weill Cornell Medicine/New York-Presbyterian Hospital in New York, and colleagues reported online in Annals of Internal Medicine. The 5-year RCC-specific survival rate was slightly lower for PA compared with partial nephrectomy (PN): 95% vs 98%.
The 5-year overall survival (OS) rates were similar for PA and RN (74% vs 75%) and lower for PA than PN (77% vs 86%).
In adjusted analyses, RCC-specific and all-cause mortality risk did not differ significantly between PA and RN. PA was associated with a non-significant 2-fold increased risk of RCC-specific mortality and a significant 2-fold increased risk of all-cause mortality compared with PN.
The cumulative rates of renal insufficiency 31 to 365 days after PA, PN, and RN were 11%, 9%, and 18%, respectively. Rates of non-urologic complications within 30 days after PA, PN, and RN were 6%, 29%, and 30%, respectively.
The authors concluded that appropriately selected older patients with small renal tumors may expect oncologic outcomes from PA similar to those of RN, with fewer complications and less chronic renal insufficiency. “Although our conclusions about the comparability of oncologic outcomes for PA versus PN are less certain, our findings suggest that patients who receive ablation might have fewer complications,” Dr Talenfeld and his colleagues wrote. “This large, population-based, comparative analysis of PA outcomes strengthens the findings of recent institutional studies and raises the level of evidence in support of PA for well-selected older patients with small renal tumors.”
For the study, the investigators used the SEER (Surveillance, Epidemiology, and End Results) cancer registry linked to Medicare claims data. The median follow-up for the whole cohort was 52 months for overall survival and 42 months for RCC-specific survival. The median follow-up for the PA, PN, and RN groups was 44, 51, and 55 months, respectively, for OS and 33, 40, and 46 months, respectively, for RCC-specific survival.
In a discussion of study limitations, the investigators pointed out that their use of SEER-Medicare linked files prevented analysis of patients who received treatment after 2011, “possibly reducing generalizability to the newest PA, PN, and RN techniques.”
Talenfeld AD, Gennarelli RL, Elkin EB, et al. Percutaneous ablation versus partial and radical nephrectomy for T1a renal cancer. Ann Intern Med. 2018; published online ahead of print.