MILAN – Patients on checkpoint inhibitors who experience both dermatologic and gastrointestinal side effects may be at increased risk of further immune-related adverse events, even though they may have better odds of a favorable outcome on the cancer treatment, results of a study presented at the World Congress of Dermatology suggest.
Andrew Bowser/MDedge News
Gabriel E. Molina
The co-occurrence of dermatologic and gastrointestinal immune-related adverse events (irAEs), which was usually seen early in the course of treatment, was independently associated with favorable progression-free and overall survival in this study, said Gabriel E. Molina, a medical student at Harvard Medical School, Boston.
Compared with patients with colitis alone, those patients who had both immune checkpoint inhibitor-induced rash and colitis were at significantly increased risk of additional irAEs affecting other organ systems, according to Mr. Molina. As a result, patients with both dermatologic and gastrointestinal irAEs may warrant earlier or closer monitoring, and need prompt referral to specialty care at first sign of emerging toxicity.
“We are really excited by the possibility that this co-occurrence of rash and colitis may be a unique and early clinical marker of both high-risk irAE patients and favorable treatment response,” Mr. Molina said.
The single-center, retrospective cohort study reported by Mr. Molina included 67 patients treated with immune checkpoint inhibitors who subsequently developed colitis. Of that group, 28 (or about 42%) also had a rash induced by that treatment.
The median time from starting treatment to onset of rash was 32.5 days, according to this report. Median onset of gastrointestinal toxicity was roughly similar between the patients who also had rash, at 73 days, as compared with patients who did not have rash, at 64 days. Most rashes were grade 1-2 in severity, and were treated with topical corticosteroids in 50% of cases or with nothing at all in 43%, according to the report.
The odds of developing an additional irAE such as hepatitis or hypophysitis was 18.5 times higher in the patients who had rash and colitis as compared with those with colitis only, the researchers also found.
In multivariate analysis, the patients with both rash and colitis had longer progression-free survival (hazard ratio, 0.37; 95% confidence interval, 0.17-0.80; P = .012) and overall survival (HR, 0.20; 95% CI, 0.05-0.83; P = .026), as compared with those with just colitis, Mr. Molina reported.
This isn’t the first study to show that the occurrence of an irAE foreshadows a better prognosis. “One promising observation that has consistently emerged in the literature is that cancer patients who develop these toxicities may actually have better oncologic outcomes than those who don’t,” Mr. Molina said.
Harvard now has a multidisciplinary group, including a dermatologist, dedicated to evaluating irAEs, he said. To date, however, a minority of patients are being referred, at which point, the dermatologic toxicity may be quite severe. “There’s this belief – which is generally true – that the rashes are mild and can be treated with topical steroids. So there’s often a delay before they see us.”
While larger studies are needed to validate the findings, just tallying up toxicities isn’t going far enough, according to the investigator.
“Our ultimate goal is to bridge the translational research gap, and to use thoughtful specimen collection to one day identify, ideally at the individualized level, the irAE risk level of the patient as soon as they start their immune checkpoint inhibitor, and then reprognosticate them each time they present with a new toxicity,” Mr. Molina said.
Mr. Molina reported no conflicts of interest.