Freezing kidney tumors—using a safe minimally invasive interventional
radiology treatment that kills the cancer 100 percent effectively
without surgery—should be the gold standard or first treatment option
for all individuals with tumors that are 4 centimeters in size or
smaller. And, this treatment—interventional cryoablation—is a viable
option for people with larger tumors, according to two studies presented
at the Society of Interventional Radiology’s 34th Annual Scientific
Meeting.
"Interventional cryoablation is as effective as laparoscopic surgery
(partial nephrectomy), the current gold standard treatment, and
laparoscopic cryoablation surgery for treating renal cell carcinoma,"
said Christos Georgiades, M.D., Ph.D., interventional radiologist at
Johns Hopkins Hospital in Baltimore, Md. "We can eliminate a cancer—that
once it metastasizes can be notoriously difficult to treat and has a
low chance of cure—with a simple outpatient procedure. Eliminating
cancer at such an early stage is truly significant news for kidney
cancer patients," he added.
It’s important that individuals realize all their treatment
options—especially since the incidence of kidney cancer has been
steadily increasing in this country over the past 30 years, said
Georgiades. Approximately 54,000 people are diagnosed with kidney cancer
each year—with nearly 13,000 dying from it annually, according to
recent statistics. Most people with this cancer are older, and the
overall lifetime risk of getting kidney cancer is about 1 in 75—with men
at higher risk than women. More than 75 percent of individuals who are
diagnosed with kidney cancer have small tumors that are discovered
incidentally. "Cryoablation is a great treatment option that doctors
should discuss with patients early on," he explained.
The Hopkins studies, examining the safety and efficacy of
percutaneous (no incision) cryoablation, show the treatment’s powerful
results. "Based on the results of our three-year study, we have shown
that interventional cryoablation for kidney cancer should be the gold
standard or the first treatment option for all patients whose tumors are
4 centimeters or smaller. It should be a viable option for patients
whose cancer is even larger than that. And, ablation (or freezing) is a
very effective option for patients who cannot or do not want to have
surgery," noted Georgiades. Cryoablation’s efficacy rate—the ratio of
how many patients’ renal cell carcinoma was destroyed completely for
localized tumors by size—is 100 percent up to 4 centimeters (about 2
inches) and nearly 100 percent up to 7 centimeters (about 3 inches).
Three localized 10-centimeter (about 4 inches) tumors—large tumors that
are typically removed surgically—were treated; in two cases the tumor
was successfully killed.
"This news is especially significant for individuals with small
tumors, since more than 75 percent of patients who are diagnosed with
kidney cancer have tumors that are 4 centimeters or less in size," said
Georgiades. "These individuals can have their tumors treated completely,
effectively, without surgery, with quicker recovery and mostly on an
outpatient basis. Whatever the definition of ‘cure’ is, these results
come as close to it as possible," he noted. "At Hopkins, interventional
cryoablation is the first-line treatment for small tumors. Most of our
patients go home the same day they receive treatment with minimal
limitation on regular activities. With laparoscopic kidney surgery, a
patient remains in the hospital for several days and recovery time can
be from two to four weeks," he added. "Our studies highlight how
effective interventional radiology treatments can be—not just for kidney
cancer—but for other kinds of cancers and other diseases as well.
Interventional radiology treatments will have a significant impact on
the overall survival and benefits that patients can have from avoiding
surgery," said Georgiades.
"There is no question that interventional cryoablation, which uses
imaging to pinpoint tumors and probes to penetrate the skin to deliver
freezing cold directly to a diseased tumor, works. This interventional
treatment is not a widely known procedure yet, even to other doctors,
and some patients are going to have to pursue it on their own," said
Georgiades. The treatment is widely available in the United States at
all major institutions and some smaller institutions as well; it is
usually covered by health insurance.
Researchers followed kidney cancer patients who had received
cryoablation for three years—well beyond the established and
well-accepted one-year benchmark within the medical community to gauge
the success of a kidney tumor treatment option—since most kidney tumors
would be visible within a year with a CT scan or MRI. The use of
percutaneous cryoablation should not be limited—as it has been—to
patients who have other diseases that make surgery very high risk,
cannot undergo anesthesia, have borderline kidney function, may only
have one kidney or multiple recurring tumors or do not have any other
option, said Georgiades. "There may be a bias in the medical
community—among surgeons, primary care doctors and urologists—that
cryoablation works only for certain patients with small tumors. This is
not the case," emphasized Georgiades.
"Traditionally, laparoscopic surgery has been the main treatment
option for all renal cell cancers; it literally cuts the cancer out. The
good news is that individuals no longer need to have a kidney partially
or completed removed to treat their cancer," noted Georgiades. When
comparing the rate of complications between percutaneous cryoablation
and surgery, Georgiades said that none of the patients who had
cryoablation developed new or metastatic disease and they had fewer
complications. The minimally invasive nature of interventional
cryoablation means that it can be performed with minimal blood loss and
without an incision, just a tiny hole in the skin. The interventional
radiology treatment translates into significantly less pain, a shorter
hospital stay and more rapid recovery. This safe treatment can be
repeated, if necessary. The most common complication is a bruise around
the kidney that goes away by itself, he said.
In studying cryoablation’s efficacy, researchers looked at 90 tumors
in 84 patients. Efficacy was determined based on a tumor’s size at 3-,
6- and 12-month clinic visits and then yearly—with follow-up imaging
with CT or MRI scans. Both efficacy and three-year survival rates
approach 100 percent overall.
In studying cryoablation’s safety, Georgiades studied the results of
101 percutaneous cryoablations on 91 patients who either couldn’t
undergo surgery or elected the interventional radiology treatment. Using
computed tomography (CT) imaging, researchers could view tumors and
probes in real time. Interventional cryoablation "has an excellent
safety profile," said Georgiades.
Cryoablation is typically performed under light anesthesia, known as
sedation, by an interventional radiologist who has consulted with the
patient’s urologist. One or more hollow needles are inserted through the
skin directly into a tumor. Interventional radiologists can observe and
guide the insertion by combined use of ultrasound and CT. The needle,
or cryoprobe, is filled with argon gas, which creates an ice ball, which
rapidly freezes the tumor. The tumor is then thawed by replacing the
argon with helium. The procedure consists of two freezing and one
thawing cycle, seeking a frozen margin beyond the tumor edge to ensure
death of the entire tumor. After the cryoprobe is removed, a small
bandage is placed over the skin puncture site. Cryoablation, which can
also be referred to as cryo or cryotherapy, is approved by the Food and
Drug Administration for treating soft tissue tumors, such as renal cell
cancer.
Source : Society of Interventional Radiology