Clinical significance of aetiological heterogeneity in classical Hodgkin lymphoma

In this review we present contemporary understanding of aetiological heterogeneity in Hodgkin lymphoma, discuss how this may influence tumour phenotype and whether it does or may impact treatment outcomes. Many new treatments are being tested in this era. We especially discuss T-cell therapy and immune checkpoint blockade, because these two modern treatments are expected to have differential efficacy by the presence/absence of Epstein-Barr virus in the malignant Hodgkin-Reed-Sternberg cells. Survival after Hodgkin lymphoma is excellent in many patient strata with first-line treatment, but less so for patients with refractory or relapsing disease. On the other hand, this good prognosis also means that very large trials are needed to demonstrate superior efficacy of new treatment regimes. And our understanding of aetiological heterogeneity in Hodgkin lymphoma and how it affects prognosis is hampered for the same reason. We discuss the potential for fine-tuning risk stratification and treatment based on information that is little used today.