Primary therapy and relative survival in classical Hodgkin lymphoma: a nationwide population-based study in the Netherlands, 1989-2017.

Population-based studies of classical Hodgkin lymphoma (cHL) in contemporary clinical practice are scarce. The aim of this nationwide population-based study is to assess trends in primary therapy and relative survival (RS) during 1989-2017. We included 9,985 patients with cHL. Radiotherapy alone was virtually not applied as from 2000 among patients aged 18-69 years with stage I/II disease, following the broader application of chemotherapy combined with radiotherapy. Chemotherapy only was the preferred treatment for patients with stage III/IV disease. Throughout the entire study period, around 20% of patients aged ≥70 years across all disease stages received no anti-neoplastic therapy. The most considerable improvements in 5-year RS were confined to patients aged 18-59 years. Five-year RS for patients with stage I/II disease diagnosed during 2010-2017 was 99%, 98%, 100%, 93%, 84%, and 61% for patients aged 18-29, 30-39, 40-49, 50-59, 60-69, and ≥70 years, respectively. The corresponding estimates for stage III/IV disease were 96%, 92%, 90%, 80%, 58%, and 46%. Collectively, the improvements in survival likely relate to advances in cHL management. These achievements, however, do not seem to translate into significant benefits for patients ≥60 years. Therefore, novel therapies are urgently needed to reduce excess mortality in elderly cHL patients.