PB0921 - Patients with non-CVC symptomatic venous thrombotic events have significantly inferior survival outcomes in pediatric cancer patients: A population-based study

Background: Venous thrombotic events (VTE) are well recognized complications in pediatric oncology patients. Central venous catheters (CVCs), are known to increase the risk of VTE. Data addressing the association of survival with symptomatic and incidental CVC related VTE is limited.

Aims: To assess the survival in patients with non-CVC symptomatic VTE (ncsVTE), non-CVC incidental VTE (nciVTE), CVC symptomatic VTE (csVTE), CVC incidental VTE (ciVTE), and no VTE patients.

Methods: After research Ethics Board approval, this study included data for all patients diagnosed between 2005-2020 from the Maritime Provinces Nova Scotia, New Brunswick, and Prince Edward Island. Kaplan-Meier survival curves were computed to assess survival in ncsVTE, nciVTE, csVTE, ciVTE, and non-VTE patients. Information on ncsVTE patients included data from 2000-2020 from the Atlantic Provinces, Nova Scotia, New Brunswick, Prince Edward Island, and Newfoundland. Outcome was compared with the log-rank test.

Results: The survival data included 771 patients with a male to female ratio of 53:47. There were 16 (2.1%) ncsVTE, 27 (3.5%) csVTE, 43 (5.6%) nciVTE, 14 (1.8%) ciVTE, and 670 (87%) no VTE patients. The male to female ratio for ncsVTE patients was 81:19, csVTE was 63:37, nciVTE 40:60, ciVTE 29:71, and no VTE 54:46. The mean age (days) at diagnosis for patients with ncsVTE was 238 ± 131 days, for patients with csVTE was 219±118 days, for patients with nciVTE was 227±104 days, for patients with ciVTE was 208±132 days, and no VTE patients was 288±97 days. The ncsVTE patients had significantly inferior survival (mean:69.4±13.3 months) in comparison to csVTE (mean:145.9±11.4 months) (p=0.018), nciVTE (mean:144.2±9.1 months) (p=0.004), ciVTE (mean:147.7±10.7 months) (p=0.018), and non-VTE (p < 0.001) patients (mean:149.2±2.3 months) (Figure 1).

Conclusion(s): This study demonstrates that pediatric oncology patients with non-CVC related symptomatic VTE have significantly inferior survival outcomes. Further data is needed to correlate VTE, disease severity, treatment intensity and inferior outcomes.