Anti-Swelling Drug Suppresses Immune System, Undermines Brain Cancer Treatment

New research reveals dexamethasone may significantly hinder immunotherapy effectiveness.

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A widely prescribed steroid used to control brain swelling in cancer patients may be undermining their treatment, according to new research.

Scientists found that dexamethasone, routinely administered to people with brain tumors, significantly suppresses immune function, potentially rendering immunotherapy treatments ineffective.

Dexamethasone is also used to treat various other conditions, such as inflammation (swelling), allergies, arthritis, allergies, and skin conditions.

Swelling caused by brain cancer is a serious issue that can lead to severe consequences, including death.

Swelling Relief Comes at Immune Cost

Dexamethasone, a potent corticosteroid typically administered intravenously to brain cancer patients, has long been the standard treatment for managing dangerous swelling. However, the new study, published in Nature, raises concerns about this common practice.

Researchers from Canada and the United States discovered that while dexamethasone effectively reduces swelling, it simultaneously creates a hostile environment for the body’s natural cancer-fighting abilities.

They analyzed brain tumor cells to understand how cancer affects immune responses, examining individual cells and where they are located. The team focused on myeloid cells, a major component of the body’s defense against brain tumors called gliomas.

Scientists discovered that immune cells in brain tumors have specific locations depending on their role. They identified two types of immune-suppressing cells: one found in areas of dead tissue and another linked to dexamethasone anti-swelling therapy. This second discovery provides a direct mechanistic link between the anti-swelling treatment and compromised immune function.

The researchers wrote that while using the body’s own immune system to fight brain tumors is “arguably” the best hope for a cure, these tumors create a situation where the immune system is weakened and filled with cells that stop it from working.

Patients who’d been treated with dexamethasone exhibited weaker immune responses. The effect was found to increase with higher doses of the medication.

All corticosteroids are immunosuppressive, Dr. Charles Couturier, a neurosurgeon and scientist specializing in brain tumors at Montreal Neurological Institute-Hospital (The Neuro) and lead study author, told The Epoch Times. “Dexamethasone happens to be the one used in brain cancer,” he added. “And is a particularly potent one.”

When the researchers exposed normal myeloid cells to dexamethasone, they observed that these cells rapidly became immunosuppressive, with effects persisting for weeks after discontinuation of the steroid.

Need for Caution in Prescription Practices

“The study is focused on brain cancer,” Couturier said. “But the findings could apply to many types of cancers.”

He pointed out that this study’s findings show that “most of the myeloid states we found are also present across different types of tumors, including the one that responds to dexamethasone.”

“Doctors should ask themselves if dexamethasone is truly needed in each case it’s prescribed,” Couturier said. “It is important to balance the need to reduce swelling with the need for a healthy immune response. We need to start developing alternatives to dexamethasone that do not inhibit immune response in patients.”

He added that in many centers’ practices, dexamethasone is given uniformly to all brain cancer patients. “We need to start asking ourselves if a given patient truly needs it,” Couturier said, adding that “many do not.”

Corticosteroids Necessary to Treat Many Conditions

Despite the identified risks associated with dexamethasone use in brain cancer treatment, corticosteroids remain a vital class of medications for numerous other conditions.

They are powerful anti-inflammatory medicines effective in alleviating inflammation, swelling, and pain.

Corticosteroids serve as critical treatments for asthma, arthritis, and skin rashes and are routinely used to help control autoimmune diseases.

Drugs in this class may be applied locally, such as with creams, eye drops, or ear drops, or systemically through injection or pill so the medication circulates throughout the body.