In a Canadian population-based study reported in the Journal of Clinical Oncology, Gupta et al found that survivors of childhood, adolescent, and young adult cancers were not at a greater risk of COVID-19 infection or severe complications of infection compared with matched controls without cancer.
As stated by the investigators in their discussion of the study rationale, “Survivors of childhood, adolescent, and young adult cancers are at risk of late effects, including pulmonary and infectious complications. Whether survivors are at increased risk of COVID-19 infection and severe complications is unknown.”
Population-based registries in Ontario were used to identify all 5-year survivors of childhood cancer diagnosed at age 0 to 17 years between 1985 and 2014, and survivors of six common adolescent and young adult cancers diagnosed at age 15 to 21 years between 1992 and 2012. Each survivor alive on January 1, 2020, was randomly matched by birth year, sex, and residence to 10 cancer-free population controls. Population-based laboratory and health-care databases were used to ascertain COVID-19 tests, vaccinations, infections, and severe outcomes; severe outcomes were defined as emergency department visits, hospitalizations, intensive care unit (ICU) admissions, and death within 60 days. The study observation period was from January 1, 2020, to May 31, 2021.
Cancer survivors were not at increased risk of COVID-19 infections or severe sequelae. These results can inform risk-counseling of survivors and their caregivers. Further study is warranted to determine risk in older survivors, specific subsets of survivors, and that associated with novel COVID-19 variants.— Gupta et al
Overall, 12,410 survivors were matched with 124,100 controls. Among age-eligible individuals, 52.8% of survivors vs 47.0% of controls were fully vaccinated (hazard ratio = 1.23, 95% confidence interval [CI] = 1.20–1.37). A total of 3.1% of survivors vs 3.2% of controls had positive COVID-19 tests (P = .68).
In analysis adjusted for age, sex, rurality, and neighborhood income quintile, no significant differences in risk between survivors and controls with COVID-19 infection were observed for emergency department visits (14.8% vs 12.9%, adjusted odds ratio [OR] = 1.2, 95% CI = 0.9–1.6, P = .19) or hospitalizations (2.8% vs 1.7%, adjusted OR = 1.8, 95% CI = 1.0–3.5, P = .07). No survivors were admitted to the ICU or died after COVID-19 infection.
Among survivors who were infected with COVID-19, no significant associations were observed between risk of emergency department visits and exposure to radiation or chemotherapy associated with pulmonary toxicity, including pulmonary or cardiac radiation or exposure to bleomycin, busulfan, carmustine, lomustine, or anthracyclines.
The investigators concluded, “Cancer survivors were not at increased risk of COVID-19 infections or severe sequelae. These results can inform risk-counseling of survivors and their caregivers. Further study is warranted to determine risk in older survivors, specific subsets of survivors, and that associated with novel COVID-19 variants.”
Sumit Gupta, MD, PhD, of The Hospital for Sick Children, Toronto, is the corresponding author for the Journal of Clinical Oncology article.