Risk factors for symptomatic venous thromboembolism during therapy for childhood acute lymphoblastic leukemia.

BACKGROUND: Symptomatic venous thromboembolism (VTE) is an unpredictable and life-threatening toxicity, which occurs early in childhood acute lymphoblastic leukemia (ALL) therapy. Approximately 5% of children will experience VTE which is treated with anticoagulation. Asparaginase and corticosteroids are etiologic factors for VTE, however other clinical factors may modify this risk. PROCEDURE: We sought to i) assess published pre-treatment VTE risk factors ii) identify early clinical factors that were associated with VTE and iii) determine whether single nucleotide polymorphisms (SNPs) associated with VTE in non-cancer patients contributed to VTE in children with ALL. We performed a detailed, retrospective analysis of 1021 ALL patients treated between 1998 and 2013. Individual patient records were reviewed to ascertain VTE incidence and document treatment-related clinical variables. RESULTS: The incidence of VTE was 5.1%. Extremes of weight at diagnosis (<5th or >95th centile) was an independent risk factor in multivariable analysis, when added to published risk factors of age ≥10 years and mediastinal mass. When factors during induction/consolidation were considered separately: bacteremia, elevated serum gamma-glutamyl transferase and bilirubin were associated with VTE occurrence. None of the SNPs associated with VTE in non-cancer populations were significantly associated with VTE in our cohort. CONCLUSION: We found two known risk factors (age ≥ 10 years and mediastinal mass) in a large cohort of children treated for ALL and identified other factors associated with VTE such as weight extremes at diagnosis, bacteremia, and abnormal liver function which warrant further study. These VTE risk factors may form the basis of future thromboprophylaxis trials.

The wide-ranging clinical implications of the short telomere syndromes.

There is an increasing number of inherited disorders in which excessive telomere shortening underlies the molecular defect, with dyskeratosis congenita (DC) being the archetypal short telomere syndrome. DC is classically described as a mucocutaneous triad of oral leukoplakia, nail dystrophy and abnormal skin pigmentation. However, excessive telomere shortening can affect almost any organ system, so the clinical manifestations are protean, including developmental delay, cerebellar hypoplasia, exudative retinopathy, aplastic anaemia, acute myeloid leukaemia, idiopathic pulmonary fibrosis, idiopathic hepatic cirrhosis, head and neck cancer and dental abnormalities, and may be multi-systemic. Undiagnosed patients may be seen by essentially any medical subspecialist. Correct diagnosis is important to ensure appropriate management, and for initiating investigations to identify affected family members. Treatment is often supportive, with transplantation offering cure for pulmonary fibrosis or bone marrow failure. Higher rates of mortality and morbidity with transplantation often require regimen alterations, underscoring the need for correct diagnosis. Short telomeres result from mutations in genes essential for telomere maintenance (e.g. genes encoding subunits of the telomerase enzyme complex). Disease severity reflects not only the severity of the defect, but also the inheritance of short telomeres, giving rise to incomplete penetrance and genetic anticipation. Attendees of the inaugural Australian Short Telomere Syndrome Conference were updated on the current scientific and clinical understanding of these disorders, and discussed the best approach for management of these patients in the Australian context. This review will include recommendations from the conference and aims to increase awareness of short telomere disorders.

Reduced incidence of second solid tumors in survivors of childhood Hodgkin's lymphoma treated without radiation therapy.

BACKGROUND: We assessed the risk of developing second malignancies in children treated for Hodgkin's lymphoma (HL), the majority of whom received chemotherapy only. PATIENTS AND METHODS: The development of second malignancies in children with HL, treated between 1960 and 1999, was assessed. Results were obtained by both chart review and linkage with a centralized cancer registry. Tumor incidence was compared for patients treated with and without radiotherapy (RT) and with the general population. Risk factors for developing second tumors were assessed by multivariate analysis. RESULTS: Of 142 childhood HL patients, 63 had received RT and 79 had not. Overall survival was similar for both groups. Fourteen patients developed second solid tumors, 12 who had received RT and 2 treated with chemotherapy only (P <0.001), with a 30-year cumulative incidence of 24.7% [95% confidence interval (CI) 7.27-47.4] and 5.8% (95% CI 0-58.9), respectively (P = 0.01). The standardized incidence ratio for second solid tumors was 236 (95% CI 112.2-359.0) versus 43.6 (95% CI 0-103.9), respectively. Multivariate analysis showed treatment with RT was the only significant risks factor for developing second solid tumors. CONCLUSIONS: Children with HL without RT have a substantially lower incidence of second tumors than those treated with RT.