Low doses of radiation heat “cold” tumors, facilitating targeting

There are many reasons why different cancer treatments do not produce the intended results and the disease can thrive despite the best efforts. One example is a tumor that contains few immune cells, which makes most immunotherapeutic cancer treatments infectious. A new study shows how these “cold” tumors can be heated by carefully controlled doses of radiation to attract fresh immune cells that can start fighting from within. Shown.

This study was carried out by scientists at the Ludwig Cancer Institute and follows some other interesting advances in the field. research Published last year with the aim of strategically inflaming these so-called “cold” tumors. These tumors are often undetectable by the immune system and continue to harm the body, but we have shown how to “heat” these tumors to provoke an immune response by intentionally inflaming them. ..

This type of treatment falls under what is known as immunotherapy. Immunotherapy aims to overcharge the body’s immune system and improve its fight against cancer. Immunotherapy becomes a dead end when it encounters a cold tumor with few immune cells, but researchers have had some success in using high-dose radiation to target cancer cells and draw other immune cells into the mixture. doing. However, in the case of cancer that has spread to the abdomen, such as the ovaries and gastrointestinal tract, these high doses of radiation can cause serious damage to vital organs.

“We came up with the idea of ​​stressing the tumor with levels of radiation that do not kill the cells, but still put enough pressure to send a signal to the immune system.” Come to me because something bad is happening, “says research author Fernanda Elera.

This technique was first investigated in mice with advanced ovarian cancer and was effectively destroyed in tumors in combination with a cocktail of immunotherapeutic agents. This treatment actually cures 20% of mice, and analysis suggests that tumor responses are triggered by T cells, major hunters of affected cells, and other complementary immune cells that play a role in atypical immune responses. Shown.

“We started by examining in mice what happens to the microenvironment of advanced ovarian tumors when exposed to low doses of radiation, and we have seen a significant increase in the expression of drug-discoverable targets. “, Said research author Melita Irving. “It was a rational approach to treatment.”

At the same time, scientists explored the potential of this technique in human subjects through a clinical study of eight patients with metastatic prostate, ovarian, and gastrointestinal cancers that lack major immune cells. These subjects were given a cocktail of immunotherapeutic agents and their abdominal tumors were exposed to very low doses of radiation every two weeks. Some side effects associated with immunotherapy had to be managed, but tumors that were successfully targeted by radiation actually regressed, but those that were missed did not. When treatment was discontinued, the tumor recurred rapidly.

“Human studies have summarized our findings in mice,” says research author George Cucos.

Scientists continue to study the technology through this clinical trial to find out why some tumors were able to avoid treatment. Another trial is currently underway, with the use of more advanced immunotherapeutic agents and low-dose radiation in combination with experimental T-cell therapies specifically designed to target the patient’s immune cells to cancer. It contains.

“Here we show that low-dose irradiation can respond to tumors that previously did not respond to immunotherapy, and that tumor control requires both adaptive and innate immunity to work together. “It was,” said Coukos. “This is the entire environment that needs to be created within the tumor to support the killer T cells, in this case the helper T cells that were the killer.”

The study was published in the journal Cancer detection..

sauce: Ludwig Cancer Institute Low doses of radiation heat “cold” tumors, facilitating targeting

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