Many cases of early-stage kidney cancer can be treated with a relatively new, nonsurgical procedure used to destroy tumors, a study by a team led by Weill Cornell Medicine and NewYork-Presbyterian suggests.

The procedure, called percutaneous ablation, involves the insertion of a needle through the skin into a kidney tumor, followed by the heating or freezing of the tumor by the needle to destroy it. The procedure is less invasive than surgery and can often be performed in an outpatient setting, using ultrasound or CT imaging to guide needle placement.

The study, published June 26 in the Annals of Internal Medicine, evaluated outcomes for more than 4,000 early-stage kidney cancer patients, age 66 and older, from a large national registry. The investigators found that percutaneous ablation is associated with fewer complications and lower rates of renal failure for older patients compared with kidney-removal surgery, known as radical nephrectomy. The latter is typically performed in that patient population.

“For older patients with this type of early-stage kidney cancer, percutaneous ablation should be considered as an alternative to radical nephrectomy,” said lead author Dr. Adam Talenfeld, an assistant professor of clinical radiology at Weill Cornell Medicine and a radiologist at NewYork-Presbyterian/Weill Cornell Medical Center.

Kidney tumors are often detected incidentally when doctors obtain imaging studies on patients for other medical reasons. Most of these tumors are classified as stage T1a, being golf-ball sized or smaller—about a third of normal kidney length—and having not yet spread outside the organ.

The first treatment choice for T1a kidney tumors is a surgery called partial nephrectomy, which removes the tumor but spares most of the affected kidney. However, partial nephrectomy is a more complex procedure with a higher risk of bleeding and other complications.

For older patients, doctors sometimes opt for the simpler radical nephrectomy, even though that effectively halves kidney function.

“Older patients, who are already at increased risk for chronic renal failure, shouldn’t always have to get their kidney taken out for a golf-ball or smaller sized tumor,” Dr. Talenfeld said. “There really has been a need for better alternatives.”

Over the past decade, doctors increasingly have used percutaneous ablation as a treatment option for stage T1a kidney cancers, but much less frequently than the two main surgical options, due in part to the lack of comparative clinical study data. Comparing outcomes in clinical trials of early-stage kidney cancer treatments has been challenging, since these tumors tend to grow very slowly.

For the study, Talenfeld and his team analyzed information from a large patient registry kept by the National Cancer Institute and linked with each patient’s Medicare claims. Their analysis, involving 4,310 kidney cancer patients, found that 5-year survival after percutaneous ablation was essentially the same as after radical nephrectomy: about 95% kidney cancer-related survival, and 75% survival overall.

However, percutaneous ablation was associated with lower rates of new-onset chronic renal failure within the first year (11% versus 18%) and much lower rates of other complications requiring emergency department or hospital admissions within 30 days of intervention (6% versus 30%).

Percutaneous ablation also resulted in fewer complications than partial nephrectomy, though a conclusive comparison of survival outcomes was difficult since patients receiving partial nephrectomy surgery were typically significantly younger and healthier on average.

Talenfeld and his colleagues now hope to do more comparative studies of these procedures, using more recent patient data and including cost comparisons.

“These results are the best evidence we have so far in support of percutaneous ablation for T1a renal cancer,” Talenfeld said. “This study suggests that for many older patients requiring surgical treatment, percutaneous ablation should be the next choice after partial nephrectomy.”

—Jim Schnabel