Over 8 million cancer deaths occurred worldwide in 2012, with breast cancer being the largest cause of cancer-related mortality for women with almost 500,000 reported deaths. While the survival rate for women with breast cancer is greater than 90 percent in the United States, these rates are typically lower in rural areas of low- and middle-income countries (LMICs) where treatment options are scarce. It ranges from 64% in Saudi Arabia to 46% in Uganda to only 12% in The Gambia. As a result, the cancer burden and death rates are highest in LMICs. In an effort, to meet this need, this work presents the design and feasibility of a low-cost cryoablation system using widely available carbon dioxide as the only consumable.
Barriers to Treatment
The main barriers to treating breast cancer in lower-income countries, are inadequate treatment options. The current treatment pattern – surgery, chemotherapy, and radiation are often impractical or too expensive, and women in remote areas have long travel times to regional hospitals.
Cryoablation is an optimal treatment option over surgical treatments for practical use in these countries. Moreover, previous work has seen the use of cryoablation for treatment of cancers including liver, lung, prostate, and breast cancer. It is also a minimally- invasive treatment which reduces complications such as pain, bleeding, and extended recovery time.
Treatment using Carbon dioxide instead of Argon
Current cryoablation systems are too expensive for use in LMICs, with a single treatment costing more than $10,000. Furthermore, these devices depend on argon gas, which typically isn’t available in low-income countries, to form the intracellular ice crystals. With these barriers in mind, researchers at Johns Hopkins University developed a custom-designed cryoablation system optimized for use with CO2, on account of its wider availability due to the carbonated beverage industry in most rural areas.
The tool was tested by performing three experiments to determine the freezing capacity of the device and its ability to induce tumor necrosis to be effective in breast cancer treatment. Initial test was performed in an ultrasound gel tissue phantom to determine whether the device could successfully reach standard freezing temperatures to kill tissue and form consistent iceballs. The second experiment required the team to treat rats with mammary tumors, and in the last round cryoablation was performed in the liver of a pig, which has a similar temperature to a human breast.
In all the trials, a minimum temperature below -40°C was achieved killing 85% or more of tumor tissues, which is comparable to benchmark values of similar cryoablation devices in the United States.
Future Work These preliminary experiments demonstrated the feasibility of cryoablation with CO2 and opens the door for future studies for human trials treating breast cancer before it’s ready for commercial use. Thus, the introduction of such a device would shift the care paradigm in LMICs in near future by allowing for increased affordable and accessible breast cancer tr