For many years, some patients with kidney, liver, lung or prostate cancers have had access to cryoablation — a cancer treatment option used to freeze away tumor cells. Now, via clinical trials, cryoablation is showing promise as a breast cancer treatment for certain patients.
Dr. Luz Venta, a breast radiologist at Houston Methodist, hopes the success of recent clinical trials will soon lead to cryoablation becoming a standard of care for some women with breast cancer.
"With treatments like these, we can react to a new breast cancer diagnosis more specifically by incorporating all factors in the treatment decision, like the type and size of tumor and the patient's age and personal preference," Dr. Venta says. "It's a new way of thinking, where we're de-escalating treatment based on an individual patient's needs. We need to look at breast cancer as a chronic disease that waxes and wanes rather than just as an acute condition."
Dr. Venta explains how the procedure works and who might be a good candidate.
Cryoablation freezes cancer cells from the inside
"Cryo" means extreme cold, and "ablation" means removal or destruction of harmful cells like cancer. Cryoablation destroys cancer cells by freezing them with a precise application of a super-cooled probe.
The nonsurgical procedure — which is performed by a highly-trained interventional radiologist — typically lasts about 20 to 30 minutes and includes the following steps:
- The breast is numbed using a local anesthetic
- Guided by ultrasound, a thin probe is inserted directly into the tumor mass
- A small amount of liquid nitrogen or argon in the probe, rapidly cools the probe to around 40 degrees below zero
- A small ball of ice grows around the tip of the probe, freezing the cancer calls in its path
- After about 10 minutes, the ice ball is allowed to thaw for several minutes, after which process is then repeated
"During the two freeze-thaw cycles, we are dehydrating, freezing and thawing out the cancer cells," explains Dr. Venta. "The damaged cells are killed by the process of freezing, and by doing so the immune system is stimulated to help in the process of healing."
Cryoablation is safe and effective
Research studies show that the procedure is highly successful at eliminating breast cancer cells. In a recent clinical trial, only 2% of patients had a recurrence of their cancer following cryoablation.
The procedure is also very safe because the ultrasound-guided probe is very precise. The radiologist can destroy the tumor cells while minimizing damage to surrounding tissue.
"We adjust the size of the ice ball to the size of the tumor so that we can trap the tumor within the ice ball," says Dr. Venta. "We also include a tiny margin of healthy cells in our target area."
These studies also show that cryoablation has very few risks. Because there is no surgical incision, patients have no entry wound or noticeable scarring — and stitches aren't even needed. A few patients reported mild side effects such as skin burns, discomfort, swelling or bruising, but most of these symptoms dissipated soon after their procedure.
Patients and physicians reported 100% satisfaction with the cosmetic outcomes.
Dr. Venta is also excited about the body's immune response to cryoablation.
"The dying tumor cells signal the natural immune system to break down the cancer tissue," Dr. Venta explains. "We believe current studies will help us develop targeted immunotherapy drugs that can stimulate this response even further to keep the cancer from coming back."
Cryoablation is currently offered to a small subset of breast cancer patients
Cryoablation is not yet approved by the Food and Drug Administration (FDA) for malignant breast tumors. That means it's typically not covered by insurance plans, and Dr. Venta stresses that cryoablation is not a first-line treatment.
"Some of our patients have already been through chemotherapy or radiation or a lumpectomy," says Dr. Venta. "For example, I've worked with patients who have metastatic disease. We might use cryoablation to shrink a new tumor that is localized to an area within the breast."
A care team may recommend the procedure if a patient has a diagnosis of invasive ductal carcinoma (IDC) that is hormone receptor-positive and HER2-negative. Providers also consider how close the tumor is to the underside of the skin, and how well they can see the area during an ultrasound.
Dr. Venta also emphasizes that cryoablation is performed by a highly trained interventional radiologist, referred by a patient's care team. Breast cancer treatment is usually a multidisciplinary approach with oncologists, surgeons, radiation oncologists and radiologists working together for the benefit of the patient.
"The decision to offer cryoablation comes from the medical or surgical oncology team members, who have a deep understanding of their patient's history and health," Dr. Venta says. "It's a very specialized procedure that's not widely available outside of larger facilities like Houston Methodist."
