Freezing Kidney Tumors Offers Similar Survival Rate, Fewer Complications

Non-invasively freezing an early-stage kidney tumor can be as effective – and less risky – for patients than surgery, according to a new study.

Nearly all patients who qualify for the procedure called percutaneous ablation experience the same 10-year survival rate, said a team of investigators from Johns Hopkins. They also have fewer complications than patients who undergo either tumor removal (partial nephrectomy) or kidney removal (radical nephrectomy).

These findings, the team said, could potentially change medical society guidance around the treatment of early-stage kidney cancer. They published their study in the June 10 Radiology.

The Emergence of Percutaneous Cryoablation

Still a relatively new treatment for kidney cancer, percutaneous cryoablation, using an CT-guided hollow tube to freeze a tumor with argon gas, is rapidly becoming more popular as a treatment method. With nearly 74,000 new cases of renal cell carcinoma anticipated annually, the researchers said, more than 4,500 patients could undergo this non-invasive procedure each year.

“We have been doing cryoablation with increasing frequency at Johns Hopkins,” said lead study author Christos S. Georgiades, M.D., Ph.D., professor of radiology, oncology, and surgery at Johns Hopkins University. “It’s an outpatient procedure that takes about 30-to-40 minutes to perform. We observe the patient for three hours, and, then, they go home.”

Percutaneous cryoablation can only be used in certain cases, however. It is available to patients with early-stage kidney cancer that is confined to the kidney, and any tumors must be less than 4 cm in size.

Percutaneous Cryoablation vs. Surgery

Although partial nephrectomy is currently considered the standard-of-care for early-stage kidney cancer, Georgiades’ team determined the percutaneous cryoablation can be preferable. The team examined outcomes for 134 patients who underwent cryoablation for tumor treatment and compared them to patients who had surgery.

Based on that analysis, the team determined the disease-specific survival – those patients who were still alive or had died from a non-kidney cancer cause – was 94 percent at both five and 10 years after treatment. This result was similar to the survival rate reported with both partial and radical nephrectomy. The overall survival probability after percutaneous cryoablation at five and 10 years was also longer than both invasive procedures, and it produced fewer side effects in some patients.

“For certain patients, cryoablation is equivalent to surgery with fewer side effects,” Georgiades explained. “The risk of significant complications from this procedure is about 6 percent, compared to between 15 [percent] and 20 percent for surgery. In addition, recovery is much faster than with surgery.”

The team also determined the patients undergoing percutaneous cryoablation had a 2.3-percent 10-year risk of hemodialysis. This was slightly lower than the 2.5-percent-to-2.7-percent risk presented by both surgical options.

The team did note, however, that based on an age-at-diagnosis analysis, patients who have early-stage kidney cancer at age 80 did not experience the same survival benefit from any of the treatment options, including percutaneous ablation.

Alongside these findings, the team said, evidence is also growing that cryoablation produces better disease-specific survival rates than thermal ablation, particularly for kidney tumors larger than 3 cm. While additional research is still needed, the greater efficacy levels could lead medical leadership organizations to re-vamp their kidney cancer guidance, making cryoablation the preferred treatment method.

“Studies like this may convince societies to make cryoablation the go-to option, at least for early-stage kidney cancer,” Georgiades said.