Improving Survival of Patients With Hodgkin Lymphoma Over 4 Decades: Experience of the British National Lymphoma Investigation (BNLI) With 6834 Patients

Background: The management of Hodgkin lymphoma (HL) has changed markedly over the last 50 years. This is due to the expanding understanding about the biology of the disease, the development of increasingly efficacious multimodal treatment, and the recognition of how to reduce late effects. The British National Lymphoma Investigation (BNLI) was formed in the 1970s to coordinate UK research in the diagnosis and treatment of lymphoma. We describe the improvement in trial patient survival over 4 decades.

Patients and methods: This analysis is of data on 6834 patients with a de novo diagnosis of HL registered onto studies with BNLI oversight from January 1, 1970, to December 31, 2009. Patients were subdivided in 4 groups according to their decade of registration; 1970s, 1980s, 1990s, and 2000s. Because of the lengthy data collection period, there is a difference in duration of follow-up between decade groups, with median follow-up in the 1970s group of 28.2 years, 18.0 years in the 1980s group, 9.4 years in the 1990s group, and 5.4 years in the 2000s group. Comparison between data in all 4 groups is not possible beyond 13.4 years (maximum duration of follow-up in the 2000s group), and so a cutoff has been applied at 14 years. Data on overall survival, cause of death, primary treatment modality, and incidence of secondary malignancy were collected.

Results: Clear and statistically significant improvements in survival curves between the decades were present, with 10-year overall survival increasing from 62.4% in the 1970s to 89.6% in the 2000s. There was a suggestion that second malignancy and cardiac-related deaths have been reducing over time, but longer follow-up is needed for the later decades to confirm this trend.

Conclusion: Results support existing registry data demonstrating that survival for HL has improved over the 4 decades analyzed. This data set is robust and validated, and it adds valuable understanding to the reasons behind the survival curves, which are a balance between efficacious therapies and decreased death related to cardiac conditions and second malignancies.