Dr Michael Green, from the Department of Radiation Oncology at the University of Michigan (UM) in the U.S., treated many cancer patients and found that the condition worsens when the cancer spreads to the liver than to other parts of the body.
It was also confirmed that these patients rarely receive modified immunotherapy.
Through a new study, Dr. Green found that when cancer metastasizes to the liver, the liver tumor sucks up important immune cells, and immuno-chemotherapy is ineffective.In the journal Nature Medicine, on the 4th The exact cause and solution were presented.
In this study, the research team revealed that a combination of immunotherapy and radiation therapy in a mouse model in which cancer has metastasized to the liver restored immune cell function and yielded better results.
When cancer metastasizes to the liver, the liver tumor sucks up important immune cells, so immunotherapy is ineffective, and a study that combines radiation therapy and immunotherapy can reverse this. © Getty Image Bank
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If liver metastases are present, immunotherapy reactions are bad
Dr. Green, an assistant professor in the Department of Radiation Oncology, points out that “cancer patients with liver metastases rarely benefit from game-changing immunotherapy,” said Dr. Green. “This study shows that radiation therapy can reverse this resistance. There is” he emphasized. It can make a real difference in treatment outcomes.
A multidisciplinary research team at the University of Michigan’s Rogel Cancer Center, including Dr. Green, examined data from 718 patients who received immunotherapy.
Patients suffered from a variety of cancers, including non-small cell lung cancer, melanoma, urinary tract cancer, and kidney cell cancer, and cancer tumors spread to various organs such as liver and lungs.
Among these patients, patients with liver metastasis repeatedly had worse responses to immunotherapy. The problem wasn’t ebbing. These patients had more cancer throughout their body than other similar patients who did not have liver cancer.
Corresponding author Weiping Zou, Chair Professor of Surgery, Pathology, Immunology, and Biology, said, “The liver triggers a systemic immune suppression mechanism. This mechanism occurs in the liver but affects the whole body.” Explained.
A patient lying on a treatment device to receive radiation therapy. ©WikiCommons/Dina Wakulchik
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Liver suppresses certain major immune cells
The liver is one of the most common areas for cancer to spread. The liver is known to interfere with the immune response in autoimmune diseases, viral infections and organ transplants by inhibiting certain major immune cells.
Oncologists observed the lack of an immune response and found that this phenomenon also occurs in liver metastatic cancer. Dr. Green noted that liver metastasis cancer patients who received chemotherapy or targeted chemotherapy showed no worse outcomes than those with other types of metastatic cancer. “I got worse only with immunotherapy,” he said.
The researchers looked at the microenvironment of liver metastasis and found that the tumor was siphoning off T-immune cells that had to work to attack the cancer.
As a result, not only the T cells were removed from the liver, but an immune desert was formed throughout the body, and the immune system to fight tumors could not be activated in any part of the body.
A paper published on the 4th day of the medical journal Nature Medicine. ©Springer Nature / Nature Medicine
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“We plan to conduct clinical trials soon”
The research team confirmed that T cell death was stopped by direct radiation therapy to liver tumors of experimental mice with liver metastasis.
After T cells recovered, an immune checkpoint inhibitor was administered, and the immune system was activated and cancer was removed from the entire body. This was the same as that of mice that had metastasized cancer to a site other than liver.
“Identifying new immunosuppressive mechanisms and finding ways to solve them is always a difficult challenge,” said Dr. Green. “We will begin clinical trials to better understand whether these promising results work similarly in human tumor mechanisms.”
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