Childhood Hodgkin Lymphoma Treatment (PDQ®): Treatment - Health Professional Information [NCI] - General Information
Hodgkin lymphoma comprises 6% of childhood cancers. In the United States, the incidence of Hodgkin lymphoma is age-related and is highest among adolescents aged 15 to 19 years (29 cases per million per year), with children ages 10 to 14 years, 5 to 9 years, and 0 to 4 years having approximately threefold, eightfold, and 30-fold lower rates, respectively. In non-European Union countries, there is a similar rate in young adults but a much higher incidence in childhood.
Hodgkin lymphoma has the following unique epidemiological features:
- Hodgkin lymphoma has a bimodal age distribution that differs geographically and ethnically in industrialized countries; the early peak occurs in the middle to late 20s and the second peak after age 50 years. In developing countries, the early peak occurs before adolescence.
- The male-to-female ratio varies markedly by age. Children younger than 5 years show a strong male predominance (M:F = 5.3) and children aged 15 to 19 years show a slight female predominance (M:F = 0.8).[6,7]
- There are three distinct forms of Hodgkin lymphoma:
- Childhood form —occurs in individuals aged 14 years and younger. The childhood form of Hodgkin lymphoma increases in prevalence in association with larger family size and lower socioeconomic status. Early exposure to common infections in preschool appears to decrease the risk of Hodgkin lymphoma, most likely by maturation of cellular immunity.
- Young adult form —effects individuals aged 15 to 34 years. The young adult form is associated with a higher socioeconomic status in industrialized countries, increased sibship size, and earlier birth order. The lower risk of Hodgkin lymphoma observed in young adults with multiple older, but not younger, siblings, is consistent with the hypothesis that early exposure to viral infection (which the siblings bring home from school, for example) may play a role in the pathogenesis of the disease.
- Older adult form —most commonly presents in individuals aged 55 to 74 years.
- Rarely, clustering of cases of Hodgkin lymphoma within families has been reported, suggesting a genetic predisposition to the disease or a common exposure to an etiologic agent.
Epstein-Barr virus and Hodgkin lymphoma
Epstein-Barr virus (EBV) has been implicated in the causation of Hodgkin lymphoma. A large proportion of patients with Hodgkin lymphoma have high EBV titers, suggesting that an enhanced activation of EBV may precede the development of Hodgkin lymphoma in some patients. EBV genetic material can be detected in Reed-Sternberg cells from some patients with Hodgkin lymphoma.
The incidence of EBV-associated Hodgkin lymphoma also shows the following distinct epidemiological features:
- EBV positivity is most commonly observed in tumors with mixed-cellularity histology and is almost never seen in patients with lymphocyte-predominant histology.[10,11,12,13,14]
- EBV positivity is more common in children younger than 10 years [10,14] compared with adolescents and young adults.[11,12]
- The incidence of EBV tumor cell positivity for Hodgkin lymphoma in developed countries is 15% to 25% in adolescents and young adults.[13,14,15] There is a high incidence of mixed-cellularity histology in childhood Hodgkin lymphoma seen in developing countries, and these cases are generally EBV-positive (approximately 80%).