The researchers leveraged population-based clinical, healthcare, and COVID-19–related databases in Ontario, Canada, to determine the risk of COVID-19 infection and complications among survivors of childhood, adolescent, and young adult cancer. Compared with the general population, survivors of childhood, adolescent, and young adult cancer were at no increased risk of either COVID-19 infections or of requiring emergency department visits or hospitalisations after COVID-19 infection. In this population-based cohort, no survivor experienced an intensive care unit admission or death following a COVID-19 infection. The findings are published on 28 February 2022 in the Journal of Clinical Oncology.
The authors wrote in the background that survivors of childhood, adolescent, and young adult cancer are at significant risk of chronic morbidities because of their primary cancer or anticancer treatment. By age of 50 years, survivors experience an average of 4.7 severe, disabling, or life-threatening conditions. They are at risk of late effects, including pulmonary and infectious complications. It was recently noted that survivors of childhood, adolescent, and young adult cancer are at increased risk of infection-related death from all infection types.
During the COVID-19 pandemic, survivors, caregivers, and providers have been concerned that survivors of childhood, adolescent, and young adult cancer may be at greater risk of developing COVID-19 infections or complications. However, data on the risks faced by survivors during the pandemic are extremely limited. International groups have therefore only stated that survivors may be at higher risk if they have specific comorbidities, such as congestive heart failure, diabetes, or lung disease, on the basis of data from the general population and not data specific to survivors. Significant anxiety persists among survivors, given this uncertainty.
Population-based registries in Ontario, Canada, identified all 5-year survivors of childhood cancer diagnosed age 0 to 17 years between 1985 and 2014, and of 6 common adolescent and young adult cancers diagnosed age 15 to 21 years between 1992 and 2012. Each survivor alive on 1 January 2020 was randomly matched by birth year, sex, and residence to 10 cancer-free population controls. Individuals were linked to population-based laboratory and healthcare databases to identify COVID-19 tests, vaccinations, infections, and severe outcomes defined as emergency department visits, hospitalisations, intensive care unit admissions, and death within 60 days. Demographic, disease, and treatment-related variables were examined as possible predictors of outcomes.
The researchers matched 12,410 survivors to 124,100 controls. Survivors were not at increased risk of receiving a positive COVID-19 test, 386 (3.1%) versus 3,946 (3.2%), and were more likely to be fully vaccinated (hazard ratio 1.23; 95 confidence interval [CI] 1.20 to 1.37).
No increase in risk among survivors was seen in emergency department visits (adjusted odds ratio 1.2; 95 CI 0.9 to 1.6) or hospitalisation (adjusted odds ratio 1.8; 95 CI 1.0 to 3.5). No survivor experienced intensive care unit admission or died after COVID-19 infection.
Pulmonary radiation or chemotherapies associated with pulmonary toxicity were not associated with increased risk.
In this first population-based study to examine SARS-CoV-2 infections in survivors of childhood, adolescent, and young adult cancer, the study team found that survivors of childhood, adolescent, and young adult cancer were not at increased risk of COVID-19 infections or of severe sequelae after infection compared with matched general population controls. These results can be used to inform appropriate risk-counselling of survivors and their caregivers, particularly those in their thirties and younger. Further study is warranted to determine the risk in older survivors, specific subsets of survivors, and that associated with novel COVID-19 variants.
The study was supported by Institute for Clinical Evaluative Sciences, which is funded by an annual grant from the Ontario Ministry of Health and the Ministry of Long-Term Care, as well as by the Pediatric Oncology Group of Ontario which is supported by same funding bodies.
Gupta S, Sutradhar R, Alexander S, et al. Risk of COVID-19 Infections and of Severe Complications Among Survivors of Childhood, Adolescent, and Young Adult Cancer: A Population-Based Study in Ontario, Canada. JCO; Published online 28 February 2022. DOI: 10.1200/JCO.21.02592