Incidence of Venous Thromboembolism in Pediatric Cancer Patients with COVID-19: MD Anderson Cancer Center Experience

Background:

Patients with COVID-19 are at increased risk of venous thromboembolism (VTE) due to a hypercoagulable state. Multisystem inflammatory syndrome in children (MIS-C) is a unique entity in the pediatric population affected by COVID-19 which also increases the risk of VTE. This has been described in the literature and guidelines have been established across different institutions regarding anticoagulation prophylaxis. It is well known that cancer increases the risk of VTE greater than four-fold to that of the general population and, for patients receiving active chemotherapy, the risk is up to 6.5 times greater.

Studies have shown that adults patients with active cancer and COVID-19 infection had increased risk of mortality due to VTE associated complications. Contrary to that, some reports have shown that incidence of VTE does not appear to be increased in adults with cancer compared to non-cancer patients. Hence, the data is yet scarce as well as conflictive.

Anecdotally, we observed a decreased number of cases of VTE associated with COVID-19 infection in our pediatric cancer patients. There are limited studies that evaluate COVID-19 infection with VTE incidents and complications in this population. In this study, we report a retrospective analysis of pediatric cancer patients at our center during a span of three years to determine the incidence of COVID-19 infection with VTE and related complications.

Objectives:

Primary objective: Investigate the incidence of VTE in pediatric cancer patients with COVID-19 infection.

Secondary objectives: Investigate COVID-19 associated complications, comorbidities in pediatric cancer patients.

Methods:

This is a single center retrospective cohort study. Data was extracted from COVID-19 database established at MD Anderson Cancer Center since the start of the pandemic. Patients 0 to 18 years of age affected by COVID-19 infection who were seen at MD Anderson Cancer Center from March 2020 to March 2023 were included. VTE inclusion criteria was development of thrombosis event from 14 days prior up to three months after COVID-19 infection. All cancer types were included. ICD 10 codes for diagnosis of COVID-19 infection and VTE were used to search for patients meeting the above criteria. Foundry database software was used to analyze the data and validation was done by the software checks by two independent reviewers and accordingly modified our search terms.

Results:

Three cohorts ( figure 1) were identified; patients with COVID-19 infection with or without VTE (Group 1), patients with VTE with or without COVID-19 infection (Group 2), and patients with both COVID-19 infection and VTE (Group 3).

From group 1 (pediatric cancer with COVID infection with and without VTE), a total of 235 cancer patients ranging between 0 to 18 years of age were found affected by COVID-19 infection (Mean = 11.1 years, median = 12 years). The majority of patients were Caucasians (57.4%). Fifty percent of patients were male.

From group 2 (pediatric cancer patients with VTE with or without COVID-19 infection), 272 patients were identified who had developed VTE of which 55.5% were males, and 54% were Caucasians with similar age distribution (mean = 13.1 years, median =15 years).

In our study population, we identified three patients with VTE events who had COVID-19 infection (group 3, see table 1).

Conclusion:

The incidence of VTE in pediatric cancer patients affected by COVID-19 infection was lower compared to COVID-19 negative pediatric cancer patients. Our findings suggest that COVID-19 infection does not appear to be an additional risk factor for the development of VTE in pediatric cancer patients.

Further studies are currently ongoing to investigate co-morbidities and COVID-associated complications other than VTE.