Freezing gas kills breast cancer cells
A new technique of freezing away breast cancer offers hope of a safe non-surgical cure for the disease, research suggests.
The technique involves inserting several needle-like "cryoprobes" into the tumour and passing super-cold gas through them.
An "ice ball" is rapidly created around each site which kills off the cancerous cells.
Unlike earlier versions of freezing therapy for breast cancer, the procedure is minimally invasive and requires no surgery.
Results from the first long term study of "image-guided multi-probe cryotherapy" for breast cancer highlighted its potential as a curative treatment.
Thirteen women with breast cancer who received the therapy remained cancer-free up to five years later.
Doctors saw no sign of the disease returning and noted no significant complications.
Lead researcher Dr Peter Littrup, from the Barbara Ann Karmanos Cancer Institute in Detroit, US, said: "Minimally-invasive cryotherapy opens the door for a potential new treatment for breast cancer and needs to be further tested.
"When used for local control and/or potential cure of breast cancer, it provided safe and effective breast conservation with minimal discomfort for a group of women who refused invasive surgery or had a local recurrence and needed additional management.
"This is the first reported study of successfully freezing breast cancer without having to undergo surgery afterward to prove that it was completely treated."
Each year more than 45,000 women in the UK are diagnosed with breast cancer and around 12,000 die from the disease.
The "gold standard" treatment for breast cancer is surgery, which offers the best chance of a cure. But removal of one of more breasts, and even surgery to cut out malignant tissue, can have a profound psychological impact on patients.
Chemotherapy and radiotherapy also have serious drawbacks in the form of complications and side effects.
Some women with breast cancer refuse to have surgery or harsh therapies, despite the consequent risks.
Freezing therapy for breast cancer is not new, but has been slow to develop.
Generally the technique has involved an operation and been applied by surgeons. Only in the last few years have the cryoprobes become small enough to be inserted through a small nick in the skin without the need for surgery.
During the procedure the physician is guided by ultrasound or CT (computerised tomography) X-ray scans.
The findings were presented today at the annual meeting of the Society of Interventional Radiology in Tampa, Florida, US.
Previous cryotherapy studies had all used a single cryoprobe and suggested that tumours larger than 1.5 centimetres could not be adequately treated, said Dr Littrup.
This was surprising bearing in mind the way men with prostate cancer were treated with cryotherapy, he said. Prostate treatment used more than six probes to freeze the entire gland, which measures around five centimetres across.
"We simply translated this concept to breast cancer in order to assure deadly temperatures well beyond all apparent tumour margins in order to generate successful use of cryotherapy in women," said Dr Littrup.
"This emphasises the important role of an interventional radiologist in pioneering image-guided therapy by appropriately using established treatment technology - let alone emerging ones - to deliver a sufficient treatment dose, rather than only relying on the organ-specific expertise of other sub-specialised physicians."
A total of 25 tumour sites were treated in the 13 patients using only local anaesthesia with mild sedation.
Dr Caitlin Palframan, from the charity Breakthrough Breast Cancer, said: "Cryotherapy is an experimental technique which is being looked at as a potential alternative to surgery for treating breast cancer. However, we are a long way away from knowing whether cryotherapy has potential as a treatment option. Where appropriate, surgery remains a gold standard treatment and surgical techniques continue to improve all the time."