The superior survival seen among patients with Hodgkin Lymphoma treated in clinical trials can be largely explained by the differences in baseline characteristics, particularly younger age, 20 year results from the EORTC-Netherlands cancer registry show.
People with Hodgkin lymphoma who were treated as part of a clinical trial had an 8% superior crude 10-year overall survival compared to those treated in routine practice (85% vs. 77%, respectively), a finding that remained in the 20th year of follow-up (73% vs. 65%), the retrospective cohort study linking two large databases showed.
However after adjusting for the age difference in the two populations the survival gap decreased to 3% in the 10th year (81% vs. 77%) and to 2% in the 20th year after diagnosis (67% vs. 65%).
“The observed survival advantage in HL trial participants can be largely explained by their better baseline characteristics, particularly younger age,” the researchers wrote in the study published in the British Journal of Haematology.
Interestingly, patients diagnosed between 1996 and 2004 and treated in the non-trial setting experienced a similar survival rate as trial participants treated between 1986 and 1995.
This finding indicated a “take-up of survival benefit” from clinical trials to non-trial populations, the researchers said.
“The combination of chemotherapy and radio-therapy was increasingly administered to trial participants, from 36% in 1986–1995 to 78% in 1996–2004, echoed by a similar, albeit, on lower percentage, increase from 15% to 42% in patients treated in the general settings” they added.