Cooling down brain tumor cells could lead to better cancer survival rates, a promising study in rats suggests.
Biomedical engineers at Duke University in Durham, North Carolina, lowered the temperature of cancer cells first in a test tube and then in live rats.
The target cancer was glioblastoma, a malignant brain tumor resistant to treatment. They discovered that at 20°C the tumor cells stopped growing.
The cancer is highly deadly, with only about 40 percent of people diagnosed surviving the first year. Only 17 percent survive beyond year two. The technology being used could be a huge boon to brain cancer patients, whose available treatments are typically expensive and physically taxing.
The development comes just days after a team at Columbia University developed a device that can beam chemotherapy treatments directly into brain tumor cells without killing healthy neurons.
A probe enters the tumor cell in a rat’s brain, where it effectively lowers the temperature of the cells, preventing them from dividing and replicating.
The device under study was not designed or approved for use in humans, but the above shows what the device would look like in concept. Its arrival would be a huge boon to brain cancer patients who are limited in available treatments.
The team of researchers, that published their findings Wednesday in the journal Science, devised a new way to stop the growth of glioblastomas.
They first isolated human and rat glioblastoma cells in a petri dish and used a device to slowly lower temperatures from 37°C, 30°, 25° to 20°C (98.6°F to 68°F).
The drop to 30° reduced the rate at which tumor cells grew in rats. At 25°, the human cancer cells stopped growing.
But it wasn’t until the glioblastoma cells in rats dropped to 20°C that they stopped growing.
The researchers then tested lower temperatures in live rats with glioblastomas.
They were able to behave, move and eat normally, a promising sign that human subjects can continue their normal lives over time while receiving treatment.
Most of the treated rats survived at least twice as long as the untreated rats.
Hypothermia as a means to stop tumor growth is not new. Although the therapy usually involves subzero temperatures.
The current standard use for hypothermia in cancer care is cryosurgery, a method that dates back to the 1940s.
The doctor inserts an instrument called a cryoprobe, which has been made ice-cold using liquid nitrogen.
The cold instrument can destroy abnormal tissues, such as tumors.
A major drawback of such a procedure is the risk of accidentally damaging the healthy brain tissue surrounding the cancer cells.
The Duke engineers reduced the risk by stopping lowering temperatures below zero degrees.
They wrote: ‘While the hypothermia treatment showed tumor necrosis with leukocytic inflammation in the immediate vicinity of the probe, there was no apparent parenchymal damage to the adjacent brain.’
The mainstay treatment for glioblastomas is surgery followed by heavy chemotherapy and radiation treatments.
About 13,000 Americans will be diagnosed with glioblastoma in 2022 and more than 10,000 are expected to die.
