Pediatric Lymphomas and Histiocytic Disorders of Childhood

Although there have been dramatic improvements in the treatment of children with non-hodgkin lymphoma, hodgkin lymphoma and histiocytic disorders over the past 3 decades, many still relapse or are refractory to primary therapy. In addition, late effects such as 2nd malignancies, cardiomyopathy and infertility remain a major concern. Thus, this review focuses on the current state of the science and, in particular, novel treatment strategies that are aimed at improving outcomes for all pediatric patients with lymphoma and histiocytic disorders while reducing treatment related morbidity.

Key points

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Non_Hodgkin lymphoma accounts for approximately 7% of cancers in patients under 20 years, or approximately 800 cases annually in the USA with cure rates ranging from 65% to over 90%, even for disseminated disease.
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A major challenge that needs to be overcome for the treatment of NHL is to optimize upfront treatment to prevent relapse since prognosis for patients with refractory of relapsed disease remains exceedingly poor.
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Hodgkin Lymphoma (HL) is diagnosed in approximately 1100 children and adolescents under age 20 years in the USA each year, accounting for 6% of overall childhood cancer diagnoses and its rank as the most common malignancy among adolescents 15–19 years.
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HL is one of the most curable forms of childhood cancer, with estimated 5-year survival rates exceeding 98%, yet long-term overall survival declines primarily from delayed effects of therapy necessitating the development of novel targeted therapies.
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Langerhan cell histiocytosis (LCH) occurs with similar frequency as HL and patients with high-risk disseminated disease have approximately 90% long-term survival; patients with low-risk disease have almost 100% survival but current standard of care therapy for LCH fails to cure over 50% of all patients.
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Emerging biological data support reclassification of LCH and other histiocytic disorders including ECD and JXG as myeloid neoplasias. Inclusion of patients with these diseases in cooperative pediatric cancer network trials is essential to optimize diagnostic and therapeutic strategies.