of 235 patients at Dana Farber Cancer Center, Boston.
Overall, 62.4% of the 93 women in the review and 48.6% of the 142 men experienced confirmed skin reactions, for an odds ratio (OR) of 2.11 for women compared with men (P = .01).
“Clinicians should consider these results in counseling female patients regarding an elevated risk of dermatologic adverse events” when taking checkpoint inhibitors, said investigators led by Harvard University medical student Jordan Said, who presented the results at the American Academy of Dermatology Virtual Meeting Experience.
Autoimmune-like adverse events are common with checkpoint inhibitors. Dermatologic side effects occur in about half of people receiving monotherapy and more than that among patients receiving combination therapy.
Skin reactions can include psoriasiform dermatitis, lichenoid reactions, vitiligo, and bullous pemphigoid and may require hospitalization and prolonged steroid treatment.
Not much is known about risk factors for these reactions. A higher incidence among women has been previously reported. A 2019 study found a higher risk for pneumonitis and endocrinopathy, including hypophysitis, among women who underwent treatment for non–small cell lung cancer or metastatic melanoma.
The 2019 study found that the risk was higher among premenopausal women than postmenopausal women, which led some to suggest that estrogen may play a role.
The results of the Dana Farber review argue against that notion. In their review, the investigators found that the risk was similarly elevated among the 27 premenopausal women (OR, 1.97; P = .40) and the 66 postmenopausal women (OR, 2.17, P = .05). In the study, women who were aged 52 years or older at the start of treatment were considered to be postmenopausal.
“This suggests that factors beyond sex hormones are likely contributory” to the difference in risk between men and women. It’s known that women are at higher risk for autoimmune disease overall, which might be related to the increased odds of autoimmune-like reactions, and it may be that sex-related differences in innate and adoptive immunity are at work, Mr. Said noted.
When asked for comment, Douglas Johnson, MD, assistant professor of hematology/oncology at Vanderbilt University, Nashville, Tenn., said that although some studies have reported a greater risk for side effects among women, others have not. “Additional research is needed to determine the interactions between sex and effects of immune checkpoint inhibitors, as well as many other possible triggers of immune-related adverse events,” he said.
“Continued work in this area will be so important to help determine how to best counsel women and to ensure early recognition and intervention for dermatologic side effects,” said Bernice Kwong, MD, director of the Supportive Dermato-Oncology Program at Stanford (Calif.) University.
The patients in the review were treated from 2011 to 2016 and underwent at least monthly evaluations by their medical teams. They were taking either nivolumab, pembrolizumab, or ipilimumab or a nivolumab/ipilimumab combination.
The median age of the men in the study was 65 years; the median age of women was 60 years. Almost 98% of the participants were White. The majority received one to three infusions, most commonly with pembrolizumab monotherapy.
No funding for the study was reported. Mr. Said has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.