Not all cancers are treated with radiation, chemotherapy or surgery. Immunotherapy alone or in combination with other treatments is also an option. Immunotherapy is a collective name for medications that encourage the body’s immune system to attack cancer cells. Cryoablation, similar to frozen warts, is a lesser-known method of treating tumors. Through a needle into the tumor, a very cold gas causes short periods of freezing and thawing, a process that destroys cancer cells. Previous research has already pointed to one beneficial side effect of cryoablation: not only the treated tumor, but also growths elsewhere in the body, stagnate, shrink or disappear.
He hoped to increase the chance of that happy coincidence by giving an additional immune injection in addition to cryoablation and immunotherapy. To this end, they developed a liquid containing a high concentration of imiquimod. This active substance causes a local immune response that attacks cancer cells and shrinks the tumor. When the fluid is injected into the tumor, it turns under the influence of body heat into a gelatinous substance that researchers call “Imigel.” Imigel turns the tumor into a “depot” that slowly releases its active substance.
Combination therapy
Specifically, the researchers studied mice with at least two persistent intestinal tumors or two triple-negative mammary tumors. This type of breast cancer is very difficult to treat and has a worse prognosis than other types. Only one in eight patients with this aggressive form of breast cancer is still alive five years after diagnosis. In this study, scientists treated a group of mice with a combination of cryoablation, immunotherapy, and ImGel. For comparison, the second group of mice received only cryoablation and immunotherapy. The third group received combination treatment using a gel that did not contain any active ingredient, to ensure that the gel itself had no effect. The researchers treated one tumor at a time and then analyzed the animals for three months.
For mice with colon cancer, adding Imigel increased the survival rate from 21 to 57 percent. For breast cancer, the survival rate increased from zero to five percent. The gel that did not contain the active ingredient had no effect on the chance of survival. Although the treatment is not flawless, the results are great. Mice that responded to the treatment were completely tumor-free after three months: non-injected tumors were also successfully treated.
Although this technology still needs to be tested on humans, researchers are positive. According to them, the fact that the treatment can have an effect on different tumors without treating them individually offers perspective. Although a lot of additional research is still needed, says Lise Aloncius, a researcher at the VUB Brussels Center for Immunology and the VIB Center for Inflammation Research. “In this study, the treatment was tested on tumors located in the same tissue (the second tumor consists of the same cells as bowel cancer or breast cancer, ed.).” It is assumed that metastases in other tissues are difficult to destroy as a side effect. We hope that future research will focus on this matter.
It remains to be seen whether Imigel can also help treat tumors in different tissues. Furthermore, the treatment has only been tested on mice. “It will be difficult to translate the results from this mouse model to humans. Tumors develop differently in humans than in mice. For breast cancer, for example, the survival rate in mice is much lower than in humans, while the opposite may be true.” Applies to intestinal tumors.
