Inherited Thrombophilia and Risk of Thrombosis in Children with Cancer: a Single-center Experience.

OBJECTIVES: Thrombosis is an increasingly recognized complication of childhood malignancy and its treatment. The incidence and etiology of pediatric cancer-related thrombosis is still not well understood. The aim of this study was to evaluate the prevalence of common prothrombotic genetic conditions in children with cancer, the frequency of thrombosis, and the role of inherited thrombophilia in the development of thrombosis in a pediatric oncology population.

PATIENTS AND METHODS: Forty-seven children (36 treated for hematological malignancies and 11 for solid tumors) with a median age of 8.8. years (range 0.4 - 19.3 years) were included in the study. Genetic polymorphisms of Factor V Leiden (G1691A), prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T were determined by real-time polymerase chain reaction-based DNA analysis.

RESULTS: Four (8.5%) patients were heterozygous for Factor V Leiden, 3 (6.4%) were heterozygous for prothrombin G20210A mutation, and 3 (6.4%) were homozygous for MTHFR C677T mutation. All patients had implanted central venous catheters. Four (8.5%) children had documented thrombosis, three of which were in the upper venous system. Two of the four patients with thrombosis had Factor V Leiden heterozygosity.

CONCLUSIONS: Thrombosis is an important complication of childhood cancer. The risk of thrombosis may be increased in patients with Factor V Leiden. In the absence of consensus guidelines, our results support the recommendation for thrombophilia screening in children with cancer.