Credit: Sue Campbell
Interim results of a randomized trial suggest that omitting radiotherapy in Hodgkin lymphoma patients with an early negative PET scan can increase their risk of relapse.
Patients with stage I/II Hodgkin lymphoma who received involved-node radiotherapy after chemotherapy with ABVD (adriamycin, bleomycin, vinblastine, and dacarbazin) were less likely to relapse than patients who received ABVD alone, regardless of prognosis.
However, patients who received chemotherapy alone still had a high rate of progression-free survival (PFS), at about 95%.
John M.M. Raemaekers, MD, PhD, of the Radboud University Medical Center in Nijmegen, The Netherlands, and his colleagues reported these results in the Journal of Clinical Oncology.
“Striking the right balance between initial cure through combined-modality treatment and accepting a higher risk of late complications, and a higher recurrence rate after omitting radiotherapy in subsets of patients who will subsequently need intensive salvage treatment, is a matter of unsettled debate,” Dr Raemaekers said.
So he and his colleagues set out to evaluate whether involved-node radiotherapy could be omitted without compromising PFS in patients with stage I/II Hodgkin lymphoma who had an early negative PET scan after treatment with ABVD.
The interim analysis included 1137 patients with untreated clinical stage I/II Hodgkin lymphoma. Of these, 444 patients had favorable prognoses, and 693 had unfavorable prognoses.
Patients in each prognostic group were randomized to receive standard treatment—2 cycles of ABVD followed by radiotherapy (n=188)—or experimental treatment—ABVD alone (n=193).
For patients with a favorable prognosis and an early negative PET scan, 1 progression occurred in the standard arm, and 9 occurred in the experimental arm. At 1 year, PFS rates were 100% and 94.9%, respectively.
For patients with unfavorable prognosis and an early negative PET scan, 7 events occurred in the standard arm, and 16 occurred in the experimental arm.
One patient died from toxicity without signs of progression, but all of the remaining events were progressions. At 1 year, the PFS rates were 97.3% and 94.7%, respectively.
Although there were few events and the median follow-up time was short, an independent data monitoring committee said it was unlikely that the final results would show non-inferiority for the experimental treatment. They therefore advised that randomization be stopped for early PET-negative patients.
