What is cryoablation?
Ablation means destroying tissue and cryo means cold or freezing.
Cryoablation is the freezing of tumors to destroy them.
The freezing is achieved with liquid nitrogen which flows through a probe (needle.) The needle is inserted into the tumor under ultrasound guidance. This allows us to position it very precisely, ensuring that the tumor is at the centre of the freezing zone.
The liquid nitrogen never leaves the needle, but it causes the tissue around the needle tip to freeze rapidly. This creates a large ball of ice that engulfs the tumor. By alternating freeze and thaw cycles, the cells in the tumor are destroyed. By the end of the procedure there should be no viable cancer cells left. The progress of ice ball development is closely monitored throughout the procedure to ensure safety.
The procedure is performed after the administration of local anesthetic. The skin and deeper tissues are completely numbed prior to the introduction of the cryoablation needle. It is therefore a painless procedure. Cryoablation of a breast tumor takes 30 – 40 minutes. Patients can go home soon thereafter.
Since cryoablation involves tissue destruction, patients can expect to develop bruising of the breast that lasts usually for one to two weeks. Post procedure pain is usually mild and can be controlled with anti-inflammatories and paracetamol.
A palpable lump remains at the tumor site after cryoablation. This is scar tissue that forms after tumor destruction. It will resolve within 6 to 12 months.
Follow up studies with mammograms, ultrasound and MRI confirm the absence of any residual breast cancer.
The purpose of cryoablation is to offer an alternative to surgery for selected breast cancers.
Which breast cancers (tumors) can be treated with cryoablation?
Tumors suitable for cryoablation:
- Solitary tumors
- 2cm maximum diameter
- No lymph node spread
- Tumor not too close to skin or chest wall
- Hormone cancers
Not suitable for cryoablation
- Multiple tumors
- >2cm maximum diameter
- Tumors associated with lymph node metastases
- Tumors abutting skin or chest wall
- Non-hormone cancers i.e. HER-2 and triple negative cancers
- Ductal carcinoma in situ (DCIS)
Advantages of cryoablation
Advantages over surgery include:
- No hospital admission. This means reduced costs and infection exposure
- No general anesthesia
- Quicker recovery.
- Usually minimal post procedure discomfort
- Excellent cosmetic outcome
International experience and Clinical Trials
Internationally, there is considerable experience with cryoablation of fibroadenomas of the breast. In the last 10 years there is growing evidence for effective cryoablation of small malignant carcinomas of the breast. There is almost universal agreement across the studies that for smaller breast lesions (<1,5cm) cryoablation results in absence of residual disease and negligible recurrence in the first 3 – 5 years.
The largest (completed) clinical trial so far (ACOSOG Z1072) demonstrated >90% success rate for complete ablation of breast cancers smaller than 2cm. The ICE-3 and FROST trials are larger multi-center clinical trial based in the United States. Preliminary results show close to 100% cryoablation success in smaller cancers (≤ 1,5cm).
Professor Eiseke Fukuma is a pioneer of cryoablation based in Kameda, Japan. He has performed more than 400 procedures since 2006. Less than 1% cancer recurrence has been recorded.
In the USA there is FDA approval for treatment of fibroadenomas and cancers (on and off trial.)