Madenci AL, et al. - Among survivors of childhood cancer, researchers assessed the incidence of late-occurring venous thromboembolism (VTE) as well as the risk factors for VTE. An increased risk for VTE was observed among childhood cancer survivors across their lifespan. In these subjects, an increased mortality risk was seen with VTE diagnosis. Considering interventions that target modifiable comorbidities, like obesity, is justified, along with prophylaxis for high-risk survivors, including those treated with cisplatin and limb-sparing approaches.

Methods

• A multi-institutional cohort of 24,355 5-year childhood cancer survivors (diagnosed between 1970 and 1999; median age at last follow-up, 28.7 years [range, 5.6 to 58.9 years]; median follow-up since diagnosis, 21.3 years [range, 5.0 to 39.2 years]) and 5,051 sibling participants were included in the Childhood Cancer Survivor Study.
• Self-reported late (≥ 5 years after cancer diagnosis) VTE was assessed as the primary end point.
• Using multivariable piecewise exponential models, estimation of rate ratios (RRs) was carried out.

Results

• According to data, 1.1 and 0.5 events per 1,000 person-years (RR, 2.2; 95% CI, 1.7 to 2.8) were noted as the late VTE incidence among survivors and siblings, respectively, with 2.5 excess events per 100 survivors over 35 years.
• Among survivors, female sex (RR, 1.3; 95% CI, 1.1 to 1.6), cisplatin (reference none; 1 to 199 mg/m²: RR, 3.0 [95% CI, 1.4 to 6.5]; 200 to 399 mg/m²: RR, 1.9 [95% CI, 1.0 to 3.6]; ≥ 400 mg/m²: RR, 2.0 [95% CI, 1.2 to 3.3]), L-asparaginase (RR, 1.3; 95% CI, 1.0 to 1.7), obesity or underweight (reference body mass index [BMI] 18.5 to 24.9 kg/m²; BMI ≥ 30.0 kg/m²: RR, 1.6 [95% CI, 1.2 to 2.0]; BMI < 18.5 kg/m²: RR, 2.4 [95% CI, 1.7 to 3.4]), and late cancer recurrence or subsequent malignant neoplasm (RR, 4.6; 95% CI, 3.6 to 5.8) were identified as risk factors for VTE.
• Limb salvage (reference amputation; RR, 3.1; 95% CI, 1.2 to 7.5) and cisplatin 200 to 399 or ≥ 400 mg/m²(reference none; RR, 4.0 [95% CI, 1.1 to 14.6] and 2.9 [95% CI, 1.1 to 8.0], respectively) were found to be independently related to late VTE among lower-extremity osteosarcoma survivors.
• VTE was found to be related to increased risk for nonexternal cause late mortality (RR, 1.9; 95% CI, 1.6 to 2.3).