While the use of immune checkpoint inhibitors (ICIs) has enhanced the survival of patients with cancer, their use has also been linked with augmented risk for immune-related adverse events. To date, whether concomitant treatment with ICIs and radiotherapy increases toxic effects remains unknown. In a study recently published in the journal Cancer, researchers conducted a retrospective cohort study to explore the safety profile of ICI with radiotherapy.

In the study, researchers used a large medical claims database from 2010 to 2017. The need for corticosteroid therapy and the risk of hospitalization within 180 days of treatment with an ICI were ascertained for patients with a diagnosis of malignant melanoma or lung cancer. Patients were stratified via the use of radiation therapy (RT) within the 30 days before and after ICI therapy. The study included 1,847 and 1,321 patients with lung cancer in the medical claims and medical pharmacy claims analyses, respectively, and 1,672 and 699 patients with melanoma were included in the medical claims and medical pharmacy claims analyses, respectively.

Among the medical claims and medical pharmacy cohorts, 10.3% and 10.8%, respectively, received RT radiotherapy. Patients who were receiving programmed death (PD)-1 inhibitors were more inclined to receive more ICI infusions (range, 2-5) than those receiving ipilimumab (range, 1-2).

The authors noted that at 180 days after the last ICI infusion, receiving both radiotherapy and ICIs did not boost risk for receiving oral prednisone or methylprednisolone infusions among any subgroup. However, concomitant RT increased the risk for hospitalization for all patients receiving PD-1 inhibitors and ipilimumab (relative risk [RR], 1.8; P <.001), all patients receiving PD-1 inhibitors (RR, 1.5; P <.001), patients with lung cancer receiving PD-1 inhibitors (RR, 1.4; P <.001), and patients with melanoma receiving ipilimumab (RR, 2.0; P = .03).

The authors concluded that in patients treated with ICIs, receiving RT was not associated with a greater risk of requiring corticosteroid therapy compared with not receiving RT. However, RT was correlated with a higher risk of hospitalization, although this finding may be a result of variations in the underlying patient illness severity or oncologic disease burden at the baseline.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.

« Click here to return to Lung Cancer Update.