Pediatric cancer patients who develop multisystem inflammatory syndrome in children (MIS-C) after COVID-19 have a worse clinical course than patients without MIS-C, according to study results published in JAMA Oncology

Systemic symptoms, hospitalization, and COVID-19-related death were all more common in patients who developed MIS-C than in those who did not, researchers found.

In this multisite study, researchers evaluated data from 2035 children with cancer and COVID-19. Of these patients, 24 developed MIS-C, and they were matched to 96 control patients without MIS-C.

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Baseline characteristics of patients with and without MIS-C were similar. Most patients (64.2%) were male, 56.7% were Hispanic/Latino, 34.2% were non-Hispanic White, and 7.5% were Black. The majority of patients (83.3%) had a hematologic malignancy, 20.8% had relapsed/refractory disease, and 9.3% had a prior bone marrow transplant. The majority of patients (92.5%) were not vaccinated against SARS-CoV-2.

COVID-19 diagnosis occurred at a median age of 12.5 years in patients with MIS-C and 11 years in control patients. The median time from the most recent chemotherapy treatment to COVID-19 diagnosis was 22.5 days in patients with MIS-C and 16 days in those without MIS-C.

Symptomatic COVID-19 was more common among patients with MIS-C than among control patients (100% and 67.7%, respectively; P <.001). Systemic symptoms occurred in 79.2% of patients with MIS-C and 53.1% of control patients (P =.02). The increased risk of systemic symptoms in the MIS-C group was seen in a multivariable analysis as well (odds ratio [OR], 4.7; 95% CI, 1.4-15.8). 

All patients with MIS-C and 34.4% of patients without MIS-C were hospitalized (P <.001). Admission to the intensive care unit (ICU) occurred in 54.2% of patients in the MIS-C group and 11.5% in the control group (P <.001). 

The increased risk of hospitalization in the MIS-C group persisted in a multivariable analysis (OR, 42.9; 95% CI, 7.1-258), as did the increased risk of ICU admission (OR, 11.4; 95% CI, 3.6-36.4). 

Changes in cancer therapy were not significantly different between the MIS-C and control groups (62.5% and 50.0%; P =.27). However, in a multivariable analysis, there was an increased risk of changes in cancer therapy among patients with MIS-C (OR, 24.9; 95% CI, 6.5-94.8). 

Patients with MIS-C were more likely than control patients to die with COVID-19 as a contributing cause (20.1% vs 1.0%; P =.002).

“Given the severity of disease with MIS-C and associated changes in cancer treatment required, MIS-C is a serious outcome for children with cancer and COVID-19,” the researchers concluded. “The severity of MIS-C among children with cancer is yet another reason to encourage vaccines and other risk mitigation behaviors in this population.”

Disclosures: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Martin SD, Davis ES, Dai C, et al. Clinical features and risk factors associated with multisystem inflammatory syndrome in children with cancer and COVID-19. JAMA Oncol. Published online May 11, 2023. doi:10.1001/jamaoncol.2023.0525