The COVID-19 pandemic has brought to light new concerns for those who have survived childhood cancer. A recent study from Karolinska Institutet published in The Lancet Regional Health—Europe reveals that adult childhood cancer survivors are at a higher risk of developing severe COVID-19, even many years after their initial diagnosis.
With advancements in medical treatments, more children are surviving cancer. However, the long-term health implications for these survivors are now being studied more closely. Researchers in Sweden and Denmark conducted a registry study involving over 13,000 individuals who had been diagnosed with cancer before the age of 20 and were at least 20 years old when the pandemic began. These survivors were compared to their siblings and randomly selected individuals from the general population of the same gender and year of birth.
The findings of the study showed that childhood cancer survivors had a lower risk of contracting COVID-19 but were 58% more likely to experience severe disease if they did become infected. Severe COVID-19 was defined as the need for hospitalization, intensive care, or death related to the infection. Javier Louro, a postdoctoral researcher at Karolinska Institutet and the first author of the study, emphasized the importance of recognizing the increased risk for severe outcomes among childhood cancer survivors.
The study also highlighted the impact of different pandemic management strategies on the risk for childhood cancer survivors. In Sweden, where recommendations were favored over strict restrictions, the increase in risk for severe COVID-19 was more pronounced compared to Denmark, which implemented early and stringent measures.
The researchers suggest that childhood cancer survivors should be considered a vulnerable group in future pandemics or health crises. Recommendations could include prioritizing them for vaccination or providing special protection during periods of high transmission. Collaboration with the Danish Cancer Institute was instrumental in conducting this study.
For more information, the study titled “COVID-19 infection and severity among childhood cancer survivors in Denmark and Sweden: a register-based cohort study” can be accessed in The Lancet Regional Health – Europe (2025) with DOI: 10.1016/j.lanepe.2025.101363.
This study sheds light on the increased vulnerability of childhood cancer survivors to severe COVID-19 outcomes and underscores the importance of tailored approaches to protect this at-risk population during health crises.
