IMMUNOTHERAPIES HAVE REVOLUTIONIZED the treatment of many cancer types over the past two decades. But researchers have long suspected that steroids—which are known to suppress immune responses—could blunt their effectiveness. Evaluating whether that is true and to what extent is important: Steroids are often given to cancer patients experiencing symptoms like decreased appetite, respiratory distress, and fatigue.
A new study published July 7, 2025, in the journal Cancer Research Communications provides evidence that steroids taken at the start of treatment can indeed lower the effectiveness of immunotherapy. By studying 277 patients with non-small cell lung cancer at two California hospitals, researchers found a “profound” disparity between the 21 patients who were receiving steroids at the start of treatment with immune checkpoint inhibitors (ICIs) and the patients who didn’t receive steroids.
Most significantly, median overall survival time for patients at one hospital was 21 months for those who did not receive steroids, compared with about eight months for those who did. At the second hospital, the median survival was about 16 months compared with four months for those receiving steroids.
Fumito Ito, a surgeon-scientist at Keck Medicine of USC in Los Angeles and lead author of the study, says the results help affirm a growing body of research on using steroids at the start of ICI treatment. By adjusting for important variables such as smoking and treatment history, cancer stage, and personal characteristics, Ito says the study offers additional evidence of steroids’ effects on ICI treatment.
“Whether or not [a patient] was on steroids at the beginning of treatment was the only independent factor” that impacted outcomes in both cohorts, Ito says.
However, researchers note that steroids are an important treatment for certain symptoms. The patients receiving steroids in Ito’s study all either had brain metastases or underlying lung conditions; steroids are used to reduce inflammation from both. Ito’s research also suggests the timing of steroid administration, as well as dosage level, can significantly impact outcomes.
For example, Ito’s study found that patients who received moderate doses of steroids “did not show a significant difference” in survival times compared with the group who received none. And a 2021 study, led by hematologist-oncologist Diana Maslov, found that cancer patients who received steroids two months or more after starting immunotherapy lived an average of 25 months. Those who received steroids earlier in treatment lived about six months.
“We were looking for ways that we can use steroids as needed to keep patients safe, while still getting the best of the immunotherapy.” says Maslov, a hematologist-oncologist at Sharp Rees-Stealy Medical Group in San Diego.
Mysterious Mechanics
Maslov notes that despite steroids’ known effect of suppressing immune responses, at the time of her 2021 research, many studies had actually found no detriments to their use alongside immune checkpoint inhibitors. It is only as researchers began to apply more refined techniques and tease out variables that potential problems arose. Now, scientists still have important questions to answer about the role of timing and dosage.
For their research, Ito’s team also studied the effect in mice. They found mice that stopped receiving steroids just prior to the start of ICI therapy did not appear to have a worse outcome, an important finding in the controlled environment. Ito and colleagues say they hope the work can serve to advance a more thorough understanding of the interactions between the two treatments.
As scientists continue their hunt for answers, Maslov says that immunotherapy patients should not develop a view that all steroid use is detrimental, even if a doctor recommends it early during ICI treatment. She offers as an example people who experience lung inflammation, which if left untreated by steroids, could progress to a severe and potentially fatal stage. Cases diagnosed at a more progressed stage would then be treated with an even larger dose of steroids. Maslov urges patients not to conceal any symptoms, such as cough or trouble breathing from their doctors and instead stay in close contact about any adverse symptoms.
“Of course we want to minimize steroid use, but at the same time, they can be what patients need,” Maslov says. “And the only way for doctors to know is for that patient to communicate with them. You don’t want to wait until you can’t breathe.”
Cancer Today magazine is free to cancer patients, survivors and caregivers who live in the U.S. Subscribe here to receive four issues per year.
