Late Venous Thromboembolic Events in Survivors of Childhood Cancer: A Report from the St Jude Lifetime Cohort Study

Survivors of childhood cancer are at risk of adverse sequelae related to prior therapies. We describe the prevalence of and risk factors for late (≥5 years from cancer diagnosis) venous thromboembolism (VTE) among participants of the St. Jude Lifetime Cohort (N=5229). Prevalence of late VTE was compared between survivors and community controls (N=737) without a history of childhood cancer. Associations with treatment and clinical factors were assessed in multivariable regression models. Ninety-four (1.8% 95% CI 1.5-2.2%) survivors [median age at cancer diagnosis 9.4 years (range:0.0-20.9); 38.5 years (12-65.9) at evaluation] had 108 VTEs vs. 5 (0.7% 95% CI 0.2%-1.6%) among controls (p=0.02) (31.1 years [12.1-70.2] at evaluation). The cumulative incidence 35 years from diagnosis was highest among survivors of Hodgkin lymphoma (7.6% [95% CI 4.5%-11.8%]). Fifty-eight of 108 (53.7%) were in an extremity (upper=7, lower=51) followed by pulmonary (38, 35.2%), abdomen (n=5, 4.6%), neck (n=3, 2.8%), cerebral sinus (n=1, 0.9%), other (n=3, 2.8%). No associations with early (<5 years from cancer diagnosis) VTE were identified (p=0.7). In adjusted models, late VTE was associated with exposure to chest (OR 2.0 95% CI 1.01-4.0) and abdominal (OR 2.2 95% CI 1.04-4.8) radiation, not combined radiation fields (OR 1.2 95% CI 0.7-2.0), and sex hormone use (OR 2.2 95% CI 1.2-3.7). The prevalence of and risk for VTE are elevated among survivors of childhood cancer, particularly those treated with radiation or using sex hormones. Incorporating these factors into risk assessments may guide monitoring, prophylaxis, or interventions, particularly in high-risk situations.