All-Cause Mortality Improved by Advances in Radiotherapy for Hodgkin Lymphoma

Advances in the treatment of Hodgkin lymphoma over time has led to significantly reduced all-cause mortality rates during the first decade of follow-up for patients who received radiotherapy (RT) alone or with chemotherapy, a study published in the International Journal of Radiation, Biology, Physics has shown.

Standard treatment for early-stage Hodgkin lymphoma primarily consisted of extended range radiotherapy, but recent advances incorporate chemotherapy to smaller RT fields and have led to improved clinical outcomes and survival rates. Recent data, however, show that long-term toxicity from historical treatment and the risk of death due to cardiac disease, secondary malignancy, pulmonary disease, and Hodgkin lymphoma remain elevated in survivors.

For this study, researchers retrospectively assessed the data of 1541 patients with stage I or II Hodgkin lymphoma who received radiotherapy alone or with chemotherapy. Study patients were stratified to 3 cohorts by year of treatment (1968-1982, 1983-1992, and 1993-2007). Mean age at diagnosis was 27 years.

At the overall median follow-up of 15.2 years (67% of patients with at least 10 years of follow-up and 35% of patients with more than 20 years of follow-up), 395 patients had died from all causes, including 21 deaths from pulmonary, 70 deaths from cardiovascular, 85 deaths from Hodgkin lymphoma, and 168 deaths from secondary malignancies (25 hematologic, 143 nonhematologic).

Cumulative incidence of non-Hodgkin lymphoma mortality exceeded Hodgkin lymphoma mortality at 8.3 years.

The 15-year overall survival rates were 78%, 85%, and 88% for patients treated in 1968-1982, 1983-1992, and 1993-2007, respectively (P =.0016).

Further analysis revealed that age, B symptoms (fever, night sweats, and weight loss), and the number of sites of disease were significantly correlated with all-cause mortality in the first decade of follow up. In addition, limited radiation field therapy trended towards significance for deceased all-cause mortality in the first decade of follow-up.

Improvements in Hodgkin lymphoma treatment and smaller radiation fields in the most recent treatment era have likely led to higher cure rates and lower rates of treatment-related toxicity. The authors concluded that “current efforts toward radiation treatment reduction may further reduce long-term mortality risk in these patients.”

Reference

Patel CG, Michaelson E, Chen YH, et al. Reduced mortality risk in the recent era in early-stage Hodgkin lymphoma patients treated with radiation therapy with or without chemotherapy [published online October 5, 2017]. Inter J Oncol Bio Phys. doi: 10.1016/j.ijrobp.2017.09.048