Treating early-stage classical Hodgkin lymphoma (cHL) with a brief course of chemotherapy followed by radiotherapy (RT) results in high cure rate. In historical cohorts, RT is associated with long-term toxicity. With lower doses and smaller radiation volumes the toxicity needs to be re-evaluated. We have previously shown an absence of excess mortality (except for relapsing patients) and limited, but not eliminated, late morbidity in patients treated 1999-2005. Here, we aim to investigate the survival results and late effects in the following years.
Using a linkage of the Swedish Lymphoma Register and Swedish health registers (LymphomaBase), we identified patients aged 18-65 years, treated with 2-4 courses of doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) followed by RT during the years 2006-2015 (n=524), and matched comparators. The cohort was analysed for second cancer, diseases of the circulatory system (DCS), diseases of the respiratory system (DRS), relative survival (RS), and years of life lost, and compared with the cohort treated 1999-2005.
Hazard ratio (HR) for second cancer was not significantly elevated, for DCS it was 1.3 (95%CI, 1.0-1.8) and for the subgroup heart failure 2.6 (95%CI, 1.3-5.0). There was significant excess risk for DRS, HR 1.8 (95%CI, 1.4-2.4). There was minimal, but statistically significant, excess mortality among patients, with a RS rate of 0.98 (95%CI, 0.96-0.99) and 0.97 (95%CI, 0.95-0.99) at 5- and 10-years of follow-up, respectively. Years of life lost to cHL were in total 0.6 years/patient, but 0.90 years/patient included the first 5 years. Years of life lost to second cancer were 0.10 years/patient and 0.14 years/comparator (p=0.85), to DCS 0.15 years/patient, and 0.06 years/comparator (p=0.02).
Follow-up is too short to detect excess risk for second cancers. HR for DCS was roughly the same as in the preceding cohort, 1.3 compared to 1.5, while there is a trend towards lower risk for DRS, 1.8 compared with 2.6. Survival in this cohort is excellent. With minimal excess mortality, years of life lost is dominated by cHL, and the excess of years lost to CVD corresponds to only 15% of years lost to cHL. The results emphasize the importance of effective therapy to avoid relapses.
Ingemar Lagerlöf, Per Wikman, Gunilla Enblad, Christina Goldkuhl, Marzia Palma, Helena Fohlin, Ingrid Glimelius, Daniel Molin