Radiotherapy after chemotherapy may benefit certain patients with advanced Hodgkin lymphoma

Consolidation radiotherapy after chemotherapy improved PFS compared with no further treatment among patients with advanced Hodgkin lymphoma who had large tumors at baseline, according to results of a randomized phase 3 trial presented at European Society for Radiotherapy and Oncology Congress.

Researchers observed the benefit among patients who achieved complete metabolic response after six cycles of doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) chemotherapy.

The use of radiotherapy in this setting is controversial because of its potential toxicity and association with long-term adverse events. About 65% to 70% of patients with advanced Hodgkin lymphoma can be cured with the ABVD regimen alone.

“These patients can often have 4 or 5 decades of life expectancy ahead of them but, given this cure rate, the cancer treatment can result in a high risk [for] complications for many long-term survivors,” Mario Levis, MD, radiation oncologist at University of Turin in Italy, said in a press release. “For this reason, it’s important that we give patients the most effective treatment for curing their cancer, while, at the same time, trying to keep the toxic side effects to a minimum.”

The analysis included 354 patients from the phase 2 portion of the HD0801 study, which analyzed the efficacy of an early salvage treatment — guided by PET — of high-dose chemotherapy followed by autologous stem cell transplantation.

All these patients had a PET-negative finding after chemotherapy, and 32.7% (n = 116) had a bulky lesion at baseline.

Researchers randomly assigned the patients who had bulky lesions — including any mass with a maximum diameter of 5 cm — to receive radiotherapy or no further treatment.

Median bulky diameter was similar both the radiotherapy group (8.1 cm) and the group that received no further treatment (8.2 cm).

The intention-to-treat analysis showed similar PFS rates in the radiotherapy group and the no-further-treatment group at 3 years (86% vs. 85.8%) and 5 years (83.7% vs. 85.8%).

However, nine patients in the radiotherapy group did not receive the treatment because of decisions by their physicians, and five of them relapsed during follow up.

Results of the per-protocol analysis showed radiotherapy improved PFS by 10.3 percentage points at 3 years (91.7% vs. 81.4%) and by 7.5 percentage points at 5 years (88.9% vs. 81.5%) compared with no further treatment. The differences did not reach statistical significance, largely due to the low number of patients in whom the disease returned (five in the radiotherapy group vs. 13 in the no-further-treatment group).

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“The results do not provide definitive evidence on the role of radiotherapy after chemotherapy for patients with advanced Hodgkin lymphoma and large tumors,” Umberto Ricardi, MD, professor and radiation oncologist at University of Turin, said in a press release. “However, the improvement in survival among those who did receive radiotherapy is not negligible. We think that the next step is for a meta-analysis of this and similar randomized trials in order to increase the robustness of the information we have on the best way to treat this disease.” – by John DeRosier

Reference:

Ricardi U, et al. Abstract OC-0502. Presented at: European Society for Radiotherapy and Oncology Congress; April 26-30, 2019; Milan.

Disclosures: HemOnc Today could not confirm the authors’ relevant financial disclosures at the time of reporting.