SINGAPORE — When a 54-year-old banking and finance professional discovered that she had Stage 1 breast cancer during a routine health check earlier this year, she chose to deep-freeze the cancer.

Jolyn — not her real name as she did not want to be identified — is among the first few breast cancer patients in Singapore to have undergone a minimally invasive procedure called cryoablation, which uses extreme temperatures between -40°C and -170°C to destroy diseased cells.

It was an unconventional choice that spared her the need for surgery or the removal of her breast.

It was not a typical move because depending on the type and stage of their breast cancer and other factors, some women may choose to get rid of their entire breast once and for all. Others opt to remove just the tumour and some surrounding tissue in a surgical procedure known as lumpectomy.  

For Jolyn, she started on the treatment in March this year with consultant general surgeon ​Jendana Chanyaputhipong from The PanAsia Surgery Group.

During the procedure, the surgeon uses a thin needle called a cryoprobe and inserts it through the skin to get directly to the cancerous tumour.

Dr Jendana, whose sub-speciality is in breast surgery, said that a cooling gas is then pumped through the cryoprobe to freeze the target tissue rapidly.

During the 30-minute-or-so procedure, the tissue is allowed to thaw before a second freeze cycle is performed to ensure cancer cells are completely destroyed.

Besides PanAsia Surgery Group, Changi General Hospital (CGH) has also performed cryoablation treatment on two breast cancer patients — its first case in May last year.

The treatment is carried out as a day-surgery procedure, Dr Jendana said. Patients may choose to be awake or sedated during the surgery. 

Dr Rameysh Danovani Mahmood, a consultant from the department of diagnostic radiology at CGH, said that there are no surgical excisions involved in cryoablation and the structure of the breast is kept largely intact after the procedure.

Jolyn said that while there was some temporary discomfort due to swelling, she felt “virtually no pain” and was up and about at home after the procedure. She worked from home in the few days that followed.

“The appearance of the breast is virtually the same as before, except for the temporary swelling,” she said. “I felt close to normal even on the same day and was doing simple household tasks.

“So much so I had to remind myself not to exert myself with more laborious tasks — such as lifting anything heavy or raising my hand above shoulder height, as cautioned (by the doctor).”

THINGS TO CONSIDER BEFORE TAKING UP TREATMENT 

Breast cancer is the most common women’s cancer. About one in 11 women will develop breast cancer in their lifetime, the Singapore Cancer Society said.

Surgery is so far the gold standard of care in treating the cancer.

However, as more breast cancer patients seek less invasive treatments that minimise scarring and deformities to the breast, researchers are exploring the use of minimally invasive, non-surgical treatments such as cryoablation as an alternative to surgery for certain low-risk, early-stage breast cancers.

Dr ​Jendana said that among breast cancer patients who are fit to undergo surgery, not all are keen to go under the knife.

“Having cryoablation as an alternative to treat certain types of breast cancer is certainly attractive to researchers, as well as beneficial for the patients themselves because it is minimally invasive and causes less scarring and deformity,” she said.

Doctors would consider this therapy depending on the type of breast cancer and tumours.   

They said that the deep-freezing technique, which has been used to treat certain cancers such as “small” liver cancer and prostate cancer, has shown promise in the treatment of selected breast cancer patients.

Based on the current available evidence, Dr Rameysh, for example, said that the treatment should be reserved for:

• small, early-stage cancer, with tumours that are less than 1.5cm in size.

• tumours confined within a single site within the breast.

• cancer which is not aggressive and have not spread outside of the breasts.

This is based on short-term data from the clinical trials that look at patients with such early-stage cancer confined to their breasts.

For now, he said that cryoablation may be considered when:

• there are no other available treatment options for controlling local tumour which is confined to the organ where the cancer began; or

• in breast cancer patients who cannot safely undergo surgery for various reasons.

“For example, elderly patients with co-morbidities (other health conditions or diseases), making them a very high-risk (candidate) for surgery. They are also not suitable for other standard breast cancer treatments like chemotherapy, radiotherapy, etc,” Dr Rameysh said.

At CGH, the two patients who underwent the procedure were aged 70 years and older and would have faced “significant risks” had they undergone surgery, he added.

Patients would not be considered for cryoablation when they may be better served by standard treatment, Dr Rameysh said. They are:

• those with more aggressive tumours;

• those with ill-defined disease such as in-situ cancers, or a group of abnormal cells that may become cancerous and spread to other locations; and

• those younger than age 50.

EARLY RESULTS IN TREATED PATIENTS ‘PROMISING’ 

Dr Jendana said that cryoablation does not replace the available standard treatments for breast cancer.

“However, with the currently available short-term data — of up to five years of follow-up — the treatment has shown comparable recurrence rates (1 per cent) to that of surgical lumpectomy, as well as minimal, if any, side effects,” she said.

Dr Rameysh said that the procedure is generally better tolerated by patients compared to other ablation techniques using high temperatures or heat treatments.

“There are no reported major complications. Minor complications such as frost bite to the skin have been rarely reported,” he said.

The results of the two breast cancer patients who underwent cryoablation at CGH have been “promising”, Dr Rameysh said, because no evidence of residual tumour or recurrence is seen in patients. 

“However, it is important to note that this is fairly preliminary at this juncture, and tumour recurrence may potentially occur many years after any form of treatment,” he added.

Dr Jendana said some researchers believe that the treatment may have added benefits. At the end of the cryoablation procedure, the destroyed tissue — which would feel like a hard lump — is left inside the body and will be cleared by the body over time. This may possibly stimulate the body’s immune response.

“The immune system may learn to recognise the antigen (a foreign substance that induces an immune response in the body) that is present in the (destroyed) cancer cells. 

“Hence, if there’s a recurrence, the immune system would be able to behave like an ‘auto-vaccine’, mounting an attack against any tumour recurrence,” she said.

This is still being studied and not confirmed, she added.

POSSIBLE RISKS 

When considering the treatment, Dr Rameysh said it is important to note that there is no strong data with regards to the long-term success of the procedure.

“Data beyond five years is lacking and given this fact, selecting suitable patients (for this treatment) is therefore crucial in order not to jeopardise their chance of better survival with established standard techniques.”

At present, cryotherapy is not routinely offered to breast cancer patients at the National Cancer Centre Singapore (NCCS).

Adjunct Associate Professor Veronique Tan Kiak Mien, head of the SingHealth Duke-NUS Breast Centre, said, however, that NCCS will be embarking on a clinical trial where cryotherapy may be offered to patients with low-risk breast cancer and who are too sickly for general anaesthesia or surgery. She also leads the breast service unit at both the division of surgical oncology at NCCS and the department of general surgery at the Singapore General Hospital.

Adjunct Assoc Prof Tan added that cryotherapy for breast cancer is still considered experimental.

Results of studies in the United Kingdom, United States and Japan on the efficacy and safety of cryotherapy in the treatment of low-risk breast cancer are expected to be released only as early as 2021.

She said: “When we treat patients with cancer, we recommend treatments with proven efficacy. Cryotherapy does seem promising, but until we have data that definitively demonstrates efficacy that is at least similar to that of surgery, we offer it within a clinical trial and not as routine therapy.” 

She also said that the main risks of the cryoablation would be the incomplete removal of the cancer. If the residual disease is undetected, the cancer may continue to grow and spread.

Additionally, the optimal way of monitoring patients who undergo cryoablation and following up with them is not yet defined.

“We all understand that a woman would prefer not to have surgery to the breast. However, as we doggedly explore the less invasive, non-surgical methods… we must not lose sight of the need for oncologic safety, which is to have cancer treatment with established efficacy and safety,” the senior consultant said.

“Current proven treatments for low-risk, early-stage breast cancers are very good and many such patients are effectively cared for. One can say that the new techniques have a tough act to follow.”

MAKING AN INFORMED PATIENT CHOICE

Dr Jendana advises patients who are keen to consider cryoablation to discuss it with their surgeons to find out their eligibility and suitability, as well as to fully understand the benefits and current limitations of the procedure and long-term treatment plans.

Having undergone an unconventional treatment, Jolyn said that it is important for patients considering various treatment options to read up and weigh the pros and cons of each treatment in relation to their own case. 

Besides cryoablation, she also underwent other cancer treatments including vacuum-assisted biopsy and radiation therapy, and will be on hormone therapy for the next few years.

Vacuum-assisted biopsy is a method of removing an area of abnormal cells using a vacuum device, while radiation therapy uses high doses of radiation to kill cancer cells.

“I read up on the results and recurrence rate cited in various studies, and also consulted two other oncologists in the US (over email through personal contacts in the US) before making a decision which I felt was right for me.

“We all have a responsibility for making a decision after weighing the facts and, most importantly, consulting a doctor whom we trust,” she said.

Considered “cancer-free” now, Jolyn is relieved to have emerged from her health scare unscathed.

“As with any unwanted news of a serious health problem, (I have) renewed appreciation for all the good things in life — family, friends and the little joys in life. I feel lucky to have come through relatively unscathed, at least for now,” she said.