Researchers from Johns Hopkins University have created a new reusable device that use carbon dioxide, a widely available and affordable gas, to power a cancer tissue-freezing probe instead of industry-standard argon.
According to the study published in the journal PLOS One, the research team wanted to create a tissue-freezing tool that uses carbon dioxide, which is already widely available and hope that the device could help women with breast cancer in lower-income countries.
“Innovation in cancer care doesn’t always mean that you have to create an entirely new treatment. Sometimes it means radically innovating on proven therapies such that they’re redesigned to be accessible to the majority of the world’s population,” said the study’s first author Bailey Surtees from the Johns Hopkins University, in a statement.
The research team tested their tool in three experiments to ensure it could remain cold enough in conditions similar to the human breast and successfully kill tumour tissue.
In the first experiment, the team used the tool on jars of ultrasound gel, which thermodynamically mimics human breast tissue, to determine whether it could successfully reach standard freezing temperatures killing tissue and form consistent iceballs. The device formed large enough iceballs and reached temperatures below -40 degrees Celsius, which meets standard freezing temperatures for tissue death for conventional devices, reported the researchers.
For the second experiment, the team treated 9 rats with 10 mammary tumours. Microscopic examination confirmed that the tool successfully killed 85% or more tissue for all tumours.
Finally, the team tested the tool’s ability to reach temperatures cold enough for tissue destruction in the normal liver of a pig, which has a temperature similar to a human breast.
The study revealed that the device was successfully able to stay cold enough during the entire experiment to kill the target tissue.
While the results are promising, the device still requires additional experiments before it’s ready for commercial use. Mainly, the research team’s next steps are to ensure it can consistently kill cancer tissue under the same heat conditions as human breast tissue.
In lower-income countries, the main barriers to treating breast cancer are inadequate treatment options — with surgery, chemotherapy and radiation being impractical or too expensive — and long travel times to regional hospitals where efficient treatment is available.
Killing cancerous tissue with cold, or cryoablation, is preferable to surgically removing tumours in these countries because it eliminates the need for a sterile operating room and anesthesia, thus making it possible to local clinics to perform the procedure. It is also minimally invasive, thereby reducing complications such as pain, bleeding and extended recovery time.