OC 06.3 - Safety and efficacy of anticoagulation therapy in pediatric patients with solid tumours or lymphomas at risk of thrombocytopenia: a retrospective study

Saturday, June 22, 2024

13:30 – 13:45 ICT

Room: 111 A-C

Co-Author(s)

KT

Katherine LP Taplin

Undergraduate Student
Faculty of Health Sciences, McMaster University, Hamilton, Canada
Oakville, Ontario, Canada

Co-Author(s)

BH

Bishal Harry

Pediatrics Resident
McMaster Children’s Hospital, McMaster University, Hamilton, Canada
Hamilton, Ontario, Canada
MD

Manmeet Dhaliwal

Research Coordinator
McMaster Children's Hospital, McMaster University, Hamilton, Canada
Hamilton, Ontario, Canada

Presenting Author(s)

Andres Felipe Fajardo, MD

Pediatrics Resident PGY-4
McMaster Children’s Hospital, McMaster University, Hamilton, Canada
Hamilton, Ontario, Canada

Co-Author(s)

Uma Athale

Professor
McMaster Children’s Hospital, McMaster University, Hamilton, Canada
Hamilton, Ontario, Canada
Anthony KC Chan, MBBS

Professor
McMaster Children’s Hospital, McMaster University, Hamilton, Canada
Hamilton, Ontario, Canada
Mihir Bhatt, MD, MSc

Department of Pediatrics
McMaster Children’s Hospital, McMaster University, Hamilton, Canada
Hamilton, Ontario, Canada

Background: Patients with solid tumours or lymphomas have an increased risk of thromboembolism (TE) and thrombocytopenia due to their disease and treatments. TE prevalence in these patients is estimated at 8%, 600 times greater than in the general pediatric population. Nevertheless, anticoagulation therapy (ACT) strategies, notably evidence-based recommendations for low-molecular-weight-heparin (LMWH) dose adjustments, for patients with concurrent thrombocytopenia in the literature remain limited.

Aims: The study’s objective was to investigate the safety and efficacy of McMaster Children’s Hospital’s ACT LMWH protocol in pediatric patients with solid tumours or lymphomas and with TE who are thrombocytopenic or at risk of thrombocytopenia.

Methods: We retrospectively reviewed records of 39 patients that received LMWH at McMaster Children’s Hospital between January 2007 and December 2020 for demographics, underlying disease and treatment, TE diagnosis and treatment, platelet counts during ACT, TE outcome, and bleeding episodes.

Results: A total of 55 TEs were diagnosed in 39 patients [mean age: 7.5 years (range: 0.1-18 years)]. Symptomatic TEs occurred in 14 patients (35.9%). The most common underlying malignancies included neuroblastomas (15%), osteosarcomas (15%), and hepatoblastomas (10%). Most patients (94.9%) completed a full course of LMWH, and the median duration of ACT was 3.1 months (range: 0.4-12.0 months). During ACT, 24 procedures (92.3%) across 20 patients were completed without bleeding complications. Bleeding events occurred in 4 patients (10.3%), however none were ACT-associated: 2 occurred during surgery more than 24 hours after LMWH was stopped, 1 was cystitis-associated, and 1 was identified from blood in a patient’s stool (Anti-Xa: 1.0 U/ml, Platelets: 246x109/L). Complete resolution was achieved by 26 patients (72%), partial resolution was seen in 6 patients (16.7%), 4 patients (13.3%) remained stable, and 1 patient’s thrombus was later revealed to be a rhabdomyoma.

Conclusion(s): Full-dose LMWH ACT administration is safe and effective in pediatric patients with concurrent thrombocytopenia or risk of thrombocytopenia.