RESUMO
Venous thromboembolism (VTE) is a well-recognized complication in pediatric cancer patients. We aimed to determine the frequency of central venous catheter (CVC) removal and survival impact of children with cancer who develop VTE. After ethics approval, a retrospective population-based study of cancer patients less than 21 years between 2005 and 2020, in the Maritime Provinces Nova Scotia, New Brunswick, and Prince Edward Island was conducted. Clinical data was collected from hospital charts and online medical records. Data on demographics, cancer diagnosis and treatment, diagnosis of VTE, use of CVC, were assessed. Kaplan-Meier survival curves were computed and compared among study groups. This study included 770 patients with a male to female ratio of 1.1:1. There were 49 patients with symptomatic VTE, 49 patients with clinically unsuspected VTE, and 671 patients with no VTE. There were 15 (1.9%) non-CVC-symptomatic (ncsVTE), 34 (4.4%) CVC-symptomatic (csVTE), 40 (5.2%) non-CVC-clinically unsuspected (ncuVTE), 9 (1.2%) CVC-clinically unsuspected (cVTE), and 671 (87%) no VTE patients. The mean number of CVCs required during treatment was significantly higher among patients with VTE (p < 0.001). Both symptomatic and clinically unsuspected VTE required significantly more CVCs compared to no VTE patients (p < 0.001 and p = 0.049 respectively). Kaplan-Meier survival curves showed ncsVTE patients' survival was significantly reduced compared to all other patients (p < 0.001). This study demonstrates that pediatric oncology patients with ncsVTE have significantly lower survival. This suggests that ncsVTE may be a biomarker for increased disease burden. This study also demonstrated that clinically unsuspected VTE had significantly more CVCs placed during treatment compared to patients without a VTE, indicating the need for better screening.
RESUMO
Inconsistencies in the definition of clinically unsuspected venous thromboembolism (VTE) in pediatric patients recently led to the recommendation of standardizing this terminology. Clinically unsuspected VTE (cuVTE) is defined as the presence of VTE on diagnostic imaging performed for indications unrelated to VTE in a patient without symptoms or clinical history of VTE. The prevalence of cuVTE in pediatric cancer patients is unclear. Therefore, the main objective of our study was to determine the prevalence of cuVTE in pediatric cancer patients. All patients 0-18 years old, treated at the IWK in Halifax, Nova Scotia, from August 2005 through December 2019 with a known cancer diagnosis and at least one imaging study were eligible (n = 743). All radiology reports available for these patients were reviewed (n = 18,120). The VTE event was labeled a priori as cuVTE event for radiology reports that included descriptive texts indicating a diagnosis of thrombosis including thrombus, central venous catheter-related, thrombosed aneurysm, tumor thrombosis, non-occlusive thrombus, intraluminal filling defect, or small fragment clot for patients without documentation of clinical history and or signs of VTE. A total of 18,120 radiology reports were included in the review. The prevalence of cuVTE was 5.5% (41/743). Echocardiography and computed tomography had the highest rate of cuVTE detection, and the most common terminologies used to diagnose cuVTE were thrombus and non-occlusive thrombus. The diagnosis of cuVTE was not associated with age, sex, and type of cancer. Future efforts should focus on streamlining radiology reports to characterize thrombi. The clinical significance of these cuVTE findings and their application to management, post-thrombotic syndrome, and survival compared to cases with symptomatic VTE and patients without VTE should be further studied.