Treatment puts the freeze on breast cancer
Doctors use liquid nitrogen to freeze and destroy tumors. There’s no hospitalization, no sedation, no scarring and no pain.
When Jo Ann West learned she had early-stage breast cancer, her doctor suggested an inventive new treatment that involves no major surgery, no chemotherapy and no radiation.
The simple outpatient procedure, called cryoablation, “deepfreezes” tumors, killing cancer cells on the spot. Recovery is measured in minutes instead of months.
“It sounded like science fiction to me, but I thought, ‘why not try it?’” says West, 79. “It sure beat the alternatives.”
The retired elementary school teacher said yes, and was placed in a clinical trial designed to determine cryoablation’s effectiveness.
The study took place at 19 cancer centers across the country, including MD Anderson.
“Cryoablation has been used for years to successfully treat benign breast tumors called fibroadenomas, as well as other cancers such as prostate and kidney,” says Rosa Hwang, M.D., associate professor of Breast Surgical Oncology and principal investigator of MD Anderson’s trial site. “It worked for other cancers, so we thought, ‘let’s try it on breast cancer.’”
How it works
To perform the procedure, doctors use ultrasound imaging to guide a thin, needle-like device through the skin and into the breast tumor, where it blasts liquid nitrogen to freeze and destroy the cancerous tissue.
“Everyone in the treatment room, including the patient, watches the action in real time on the ultrasound screen,” Hwang says. “An ice ball forms around the tumor and freezes it from the inside out. It’s visually impressive.”
The regimen includes a 6- to 8-minute freeze at temperatures 40 degrees below zero or colder, followed by a 10-minute thaw, then another 6- to 8-minute freeze. Doctors then remove the probe, place a Band-Aid over the tiny incision, and the patient goes home.
The entire procedure takes less than half an hour. There’s no hospitalization, no sedation, no scarring and no pain.
“I’ve prescribed pain pills but no one fills their prescriptions,” Hwang says. “They simply don’t need to.”
Recovery is instantaneous, she says. Some women have even walked out of the hospital and gone shopping or to a restaurant.
After cryoablation, patients are seen for follow-ups, including mammograms, every six months for the first five years, then annually after that. Some may be followed more frequently, depending on their individual health.
In the multicenter trial, cryoablation was performed on women with early-stage breast cancer whose tumors were 2 centimeters or smaller.
“Before and after” MRI images were taken so doctors could examine each patient’s tumor to confirm it had been fully frozen.
Several weeks after cryoablation, the women’s now-dead tumors were surgically removed and examined so doctors could confirm that all cancer cells were killed.
The results: At all 19 cancer centers, cryoablation killed 92% of cancers — meaning no remaining cancer was found — and 100% of tumors smaller than 1 centimeter. In the MD Anderson trial, 100% of all tumors were killed.
“This is a huge advance for women,” Hwang says. “I think it could be the wave of the future.”
Boosting an immune response
Besides the advantages of no pain, no downtime and no scarring, there’s another potential perk with this technique: It appears to stimulate an anti-cancer immune response, Hwang says.
“We think that cryoablation causes tumor cells to burst and release their cancer genetic material into the body,” Hwang explains. “The patient’s immune system ramps up to attack this flood of cancer.”
Immune cells, researchers believe, will attack the primary cancer, as well as cancer cells that have spread to other areas in the body. And because the immune system “remembers” the cancer cells, it will annihilate any cancer that attempts to recur.
Researchers have confirmed this revved-up immune response in mice, and they’re preparing to test it on people.
“Only time and further research will uncover the full benefits of cryoablation for breast cancer,” Hwang says. “But right now the potential looks promising.”