While most children and adolescents with cancer have mild illness from COVID-19 infection, according to a recent analysis, some experience severe illness and a small percentage even die.
The findings, published online last month in Lancet Oncology, represent the first global registry data across income groups reporting COVID-19 outcomes in pediatric oncology patients.
“We wanted to create a global pool of evidence to answer the question: Do we see serious ones? [COVID-19] infection [in children with cancer]Corresponding author Sheena Mukkada, MD, St. Jude Children’s Research Hospital, Memphis, Tennessee, told Medscape Medical News.
In a cohort of 1,319 pediatric patients followed for 30 days, Mukkada and colleagues reported that 80% of these patients had asymptomatic to moderate COVID-19 disease, while 1 in 5 had severe or critical illness and nearly 4% died. – four times the death rate observed in published cohorts of general pediatric patients.
The results highlight that “children and adolescents with cancer generally recover from COVID-19 without incident, but may have a severe course of infection,” the authors concluded.
And because they know that some children can get very sick, the researchers wanted to “identify who these patients are so we can prioritize and protect that group,” she added.
Echoing that sentiment, Kathy Pritchard-Jones, MD, president of the International Society of Pediatric Oncology (SIOP) and co-author of the study noted in a press release that “by working together to create this global registry, we are helping hospitals have enabled around the world to quickly share and learn how COVID-19 is affecting children with cancer.”
Pritchard-Jones noted that these results generally provide reassurance that “many children can safely continue their cancer treatment, but they also highlight important clinical features that may predict a more severe clinical course and the need for greater vigilance for some patients.”
Within the global registry data
The Global Registry of COVID-19 in Childhood Cancer, jointly established by St. Jude Children’s Research Hospital and SIOP, included data from 131 institutions in 45 countries. Children recruited into the registry between April 2020 and February 2021 ranged in age from infancy to 18 years.
Most patients remained asymptomatic (35%) or developed mild to moderate illness (45%), although 20% developed severe or critical illness.
The researchers highlighted several factors associated with a greater risk of developing more serious disease from COVID-19, including cancer type, intensity of therapy, age, absolute lymphocyte count, and presence of co-morbidities or COVID-19. 19 symptoms.
Notably, more than 80% of serious or critical infections occurred in patients with haematological malignancies – with 56% of cases in patients with acute lymphoblastic lymphoma or acute lymphoblastic leukemia – followed by extracranial solid tumors (15.8%) and tumors of the central nervous system (2.7%).
In patients with acute lymphoblastic leukemia or acute lymphoblastic lymphoma, severe or critical illness was most common in those receiving induction therapy (30%), relapsed or refractory therapy (30%) and those in the maintenance or continuation phase of therapy (19% ).
Older age was associated with a higher risk of serious disease – with the lowest risk in infants (9.7%) and highest in the 15- to 18-year-old cohort (27.3%).
Patients with lymphopenia with an absolute lymphocyte count of 300 cells per mm3 or less and an absolute neutrophil count of 500 cells per mm3 or more were also at increased risk of severe disease from COVID-19.
With regard to whether the presence of lymphopenia or neutropenia should alter treatment approaches, Mukkada noted that, if possible, these patients should receive antiviral treatment, such as remdesivir, if the center has antiviral drugs, or should be given priority over hospitalization.
Adjusting cancer treatment may be recommended if patients are highly lymphopenic or have very low neutrophil counts, but a more effective strategy is simply to ensure that children and adolescents of age-matched cancer or who have had a hematopoietic stem cell transplant are fully vaccinated. against COVID-19. For children who are not yet of age, everyone around them should be vaccinated.
Pediatric patients in low- and middle-income countries were also more likely to have severe or critical outcomes from COVID-19 (41.7%) compared to patients in other income groups (23.9%).
The impact of COVID-19 “has been felt in all corners of the world, but especially in low- and middle-income countries compared to high-income countries,” senior author Carlos Rodriguez-Galindo, MD, global director at St. Jude, said in a statement. declaration.
When it comes to the intersection of cancer treatment and COVID diagnosis, nearly 83% of pediatric patients received treatment for their cancer. Chemotherapy was withheld in approximately 45% of these patients and some change in treatment regimen occurred in nearly 56% of participants receiving active therapy.
“Treatment adjustments were least common in patients from upper-middle-income countries compared to other income groups,” the authors write.
While it was an interesting observation, Mukkada noted that the registry data failed to explain why treatment adjustments were less common in upper-middle-income countries than in high- and low-income countries.
UK monitoring project
However, not all studies have shown that the COVID-19 infection is significantly more severe in children with cancer. In a 2020 report from the UK Pediatric Coronavirus Cancer Monitoring Project, researchers evaluated all children in the UK under the age of 16 diagnosed with COVID and cancer.
“[Given that] we had full coverage of every center in the UK caring for children with cancer, we are confident we picked up at least any serious or critical cases,” lead author Gerard Millen, MD, honorary clinical research fellow, University of Birmingham, Birmingham, UK, said in an email to Medscape Medical News.
Between March 2020 and July 2020, Millen and colleagues identified 54 positive cases of COVID-19, with 15 (28%) asymptomatic, 34 (63%) mild and 4 (7.4%) severe or critical – more in line with the incidence of serious illness reported in the general pediatric population.
“Fortunately, we didn’t have any children with cancer in the UK who died from COVID-19,” Millen noted. “Overall, in the UK we have taken the approach that the majority of children with cancer in this country are at very low risk for COVID-19 and we don’t have good evidence to adjust their treatment.”
Millen pointed out that the data in the UK study was “remarkably similar” to that of the high-income countries in the global St Jude/SIOP cohort, where 7.4% of patients in that cohort had severe or critical illness, compared to 7.4% of patients from their own UK cohort.
“I think many of the key differences between the two cohorts reflect the fact that access to treatment is more challenging in many low- to middle-income countries with many factors contributing to overall poorer outcomes for both cancer and non-cancer statistics,” said Millen.
Both the UK and registry studies were conducted before vaccinations became available for older children, and before the emergence of certain variants, including the Delta variant, which is responsible for the most recent increase in COVID-19 infections around the world.
Data on COVID-19 vaccination in children with cancer is limited, but so far promising.
As to whether the Delta variant could influence outcomes for children with cancer and COVID-19, Mukkada could only speculate, but she noted “what we hear anecdotally about the [Delta] Since the disease is more serious, even in patients who do not have cancer, we can say that we cannot close the registry yet. We are still actively enrolling children.”
The study was funded by the American Lebanese Syrian Associated Charities and the National Cancer Institute. The study authors and Dr. Millen have not disclosed any relevant financial relationships.
Lancet Oncology. Published online August 26, 2021. Full text
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