In the United States, cryoablation or tissue freezing to death is one primary treatment option for a variety of cancers, including those originating or spreading to the bone, cervix, eye, kidney, liver, lung, pancreas, and prostate.
Cryoablation for prostate cancer, one of the most common cancers in men, was first approved in the 1990s.
But unlike Europe, this non-surgical approach is not approved Lung cancer in the US, one of the most common cancers in women.
So why is this approach still experimental for breast cancer?
“I don’t know,” replied Richard Fine, a cryoablation researcher, a doctor at the West Cancer Center in Germantown, Tennessee, when asked. Medscape Medical News.
“It’s very interesting the FDA’s slowness in approving devices for breast cancer [when compared with] other cancers, ”he said.
New clinical data
Perhaps new clinical data will eventually lead to the approval of this laparoscopic technique for use in low-risk breast cancer. However, the related trial had a controversial design that could discourage professional participation if approved, an expert who did not participate in the study commented.
However, new data show that cryoablation may be an effective treatment for small early-stage low-risk breast cancers in older patients.
The findings come from ICE-3, a multicenter single-arm cryoablation study in 194 such patients with a mean follow-up of approximately 3 years.
He used the liquid nitrogen-based cryoablation technology of IceCure Medical Ltd., an Israeli company and sponsor of the study.
The results show that 2.06% (n = 4) of patients had a recurrence in the same breast, which is “basically the same” as lumpectomy, the surgical standard for this group of patients, said Fine, who is the trial’s lead researcher.
These are provisional data, Fine noted, when the results were presented recently at the annual meeting of the American Society of Breast Surgeons, held virtually due to the pandemic.
The main result is the five-year recurrence rate, and this is the first cryoablation trial that does not involve follow-up surgery, he said.
Cryoablation, which supplies a gas to a tumor using a thin probe resembling an ultrasound-guided needle, has multiple advantages over surgery, Fine said.
“The non – invasive procedure is quick, painless and can be delivered underneath local anesthesia to a doctor’s office. Recovery time is minimal and cosmetic results are excellent, with little loss of breast tissue and no scarring, ”she said in a press release from the meeting.
The potential market for cryoablation in breast cancer is large, as it is intended for tumors ≤ 1.5 cm, comprising approximately 60% -70% of stage 1 breast cancers that are hormone receptor positive (HR +) and HER2 negative (HER2 -), Fine said Medscape Medical News.
Cryoablation is part of a logical escalation of breast cancer care, he added. “It simply came to our notice then mastectomy to lumectomy-modified mastectomy, so the next step in this evolution is ablative technology, which is “non-surgical”. “
There are other experimental ablative treatments for breast cancer, including ultrasound and high-frequency laser, but cryoablation is the longest in development.
Cryoablation as the primary treatment for cancer was first approved for coverage by the U.S. Medicare and Medicaid Service Centers for localized prostate cancer in 1999.
But the concept extends to 1845, when English physician James Arnott first used iced salt solutions (approximately –20 ° C or -4 ° F) to induce tissue necrosis, reducing tumor size and improving pain. Because raw cryogen had to be applied topically, the pioneer the technique was limited to breast and cervical cancers for their accessibility.
He is not likely to show superiority
The population of the new study consisted of women aged 60 years or older (mean age 75 years) with unifocal invasive ductal cancers less than or equal to 1.5 cm in size who were all of low grade, HR + and HER2–, as pointed out earlier.
Liquid nitrogen-based cryoablation consisted of a freeze-thaw-freeze cycle that totals 20 to 40 minutes, with freezing temperatures directed to the tumor area and turning it into an “ice ball.”
This ice ball eventually surrounds the tumor, creating a “lethal zone” and therefore a margin where there is no cancer, similar to surgery, Fine said.
The researchers reported that no significant adverse events or complications related to the device were reported. Most adverse events were minor and included bruising, localized edema, mild burns from skin freezing, rash, minor bleeding from needle insertion, minor local bruising, skin induration, minor infection, and pruritus.
Two of the 15 patients who underwent sentinel node biopsy had a positive sentinel node. At the discretion of their treating physician, 27 patients received adjuvant radiation and 1 patient received chemotherapy and 148 began endocrine therapy. More than 95% of patients and 98% of physicians reported satisfaction with cosmetic results during follow-up visits.
Because not all patients underwent sentinel lymph node biopsy and adjuvant radiation, there is likely to be controversy over this approach, suggested Deanna Attai, MD, a breast surgeon at UCLA in Los Angeles and former president of the ‘ASBrS, who was asked for comments.
“We have studies that [indicate that] these treatments do not provide a significant benefit [in this patient population] but there is still this hesitation [to forgo them], “she said Medscape Medical News.
“Patients in this study had an extremely low risk,” he stressed.
“Is five years enough to assess recurrence rates? The answer is probably no. It is likely that recurrences or distant metastases occur 10-20 years later.”
Therefore, it will be difficult to prove that cryoablation is superior to surgery, he said.
“You can demonstrate that cryoablation is not inferior to lumpectomy alone, which allows patients to avoid surgery,” Attai summarized.
The surgical mindset and breast cancer
Attai, who did not participate in the current trial, was a researcher in a previous one-arm cooperative group study on cryoablation of breast cancer, which had as its main result the rate of complete ablation. of the tumor. The study, known as American College of Surgeons Oncology Group Z1072 of the test, 99 patients were enrolled, all of them undergoing ablation followed by surgery. The study reported results in 2014, but it developed very slowly, he noted.
“I did my first workout in 2004 and I think the study didn’t open for several years afterwards. I think there have been a lot of hesitations to change the mindset that any cancer needs to be removed surgically,” Attai said.
“When breast cancer is put in the context of other organs, we are a little behind [with cryoablation]”, added.
“I don’t want to go there, but … sometimes innovation for male diseases and procedures sometimes outweighs that of women’s diseases,” she commented.
But the UCLA breast surgeon also defended her fellow practitioners. “There have been tremendous changes in management during the 27 years I have been in practice,” he said, citing the move from mastectomy to lumpectomy as one of the many important changes.
There are not many vital structures inside the chest.
The disparity between the development of cryoablation for breast and prostate cancer is a mystery when considering possible side effects, Fine noted. “There are not many vital structures inside the breast, so you have no risks with the prostate, including urinary incontinence i impotence. “
As a next move, the ASBrS plans to establish a cryoablation registry and aims to enroll 50 sites and 500 patients aged 55 to 85 years; for those aged 65 to 70, radiotherapy it will be necessary, Fine said.
Currently, cryoablation for breast cancer is only allowed in a clinical trial, so a record would greatly increase use, he said.
Attai hopes the field is ready for the non-surgical approach.
“Halsted died in 1922 and Halsted’s radical mastectomy didn’t really begin to be wasted until the 1950s, 1960s,” said Attai, referring to Dr. William Halsted, who pioneered the procedure in the 1890s. “I hope we are better at accelerating our progress. Changing the surgical mindset takes time,” he said.
Fine was a researcher in the ICE3 trial, funded by IceCure Medical. Attai has not revealed any relevant financial relationship.
Annual Meeting of the American Society of Breast Surgeons 2021: Scientific session Oral presentation. Filed April 30, 2021.