COVID-19 in pediatric cancer patients is associated with treatment interruptions but not with short-term mortality: a Polish national study
Authors: Węcławek-Tompol Jadwiga , Zakrzewska Zuzanna , Gryniewicz-Kwiatkowska Olga , Pierlejewski Filip , Bień Ewa , Zaucha-Prażmo Agnieszka , Zając-Spychała Olga , Szmydki-Baran Anna , Mizia-Malarz Agnieszka , Bal Wioletta , Sawicka-Żukowska Małgorzata , Kruk Agnieszka , Ociepa Tomasz , Raciborska Anna , Książek Agnieszka , Szczepański Tomasz , Peregud-Pogorzelski Jarosław , Krawczuk-Rybak Maryna , Chaber Radosław , Matysiak Michał , Wachowiak Jacek , Irga-Jaworska Ninela , Młynarski Wojciech , Dembowska-Bagińska Bożenna , Balwierz Walentyna , Matkowska-Kocjan Agnieszka , Kazanowska Bernarda , Styczyński Jan , Ussowicz Marek 
Published: October 2021

Abstract
Background
Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) currently constitutes the leading and overwhelming health issue worldwide. In comparison with adults, children present milder symptoms, with most having an asymptomatic course. We hypothesized that COVID-19 infection has a negative impact on the continuation of chemotherapy and increases nonrelapse mortality.

Material and methods
This study was performed to assess the course of SARS-CoV-2 among children with hematological or oncological malignancies and its impact on cancer therapy. Records of SARS-CoV-2 infection in 155 children with malignancies from 14 Polish centers for pediatric hematology and oncology were collected and analyzed.

Results
SARS-CoV-2 replication was observed in 155 patients. Forty-nine patients were symptomatic, with the following being the most common manifestations: fever (31 patients), gastrointestinal symptoms (10), coryza (13), cough (13) and headache (8). In children who were retested, the median time of a positive PCR result was 16 days (range 1–70 days), but 12.7% of patients were positive beyond day + 20. The length of viral PCR positivity correlated with the absolute neutrophil count at diagnosis. Seventy-six patients did not undergo further SARS-CoV-2 testing and were considered convalescents after completion of isolation. Antibiotic therapy was administered in 15 children, remdesivir in 6, convalescent plasma in 4, oxygen therapy in 3 (1—mechanical ventilation), steroids in 2, intravenous immunoglobulins in 2, and heparin in 4. Eighty patients were treated with chemotherapy within 30 days after SARS-CoV-2 infection diagnosis or were diagnosed with SARS-CoV-2 infection during 30 days of chemotherapy administration. Respiratory symptoms associated with COVID-19 and associated with oxygen therapy were present in 4 patients in the study population, and four deaths were recorded (2 due to COVID-19 and 2 due to progressive malignancy). The probability of 100-day overall survival was 97.3% (95% CI 92.9–99%). Delay in the next chemotherapy cycle occurred in 91 of 156 cases, with a median of 14 days (range 2–105 days).

Conclusions
For the majority of pediatric cancer patients, SARS-CoV-2 infection does not result in a severe, life-threatening course. Our data show that interruptions in therapy are common and can result in suboptimal therapy.