Comparing long-term toxicity and efficacy of combined modality treatment including extended- or involved-field radiotherapy in early-stage Hodgkin's lymphoma.

BACKGROUND

To evaluate long-term toxicity and efficacy of a combined modality strategy including extended-field radiotherapy (EF-RT) or involved-field radiotherapy (IF-RT), the German Hodgkin Study Group carried out a follow-up analysis in patients with early unfavorable Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

One thousand two hundred and four patients were randomized to four cycles of chemotherapy followed by either 30 Gy EF- or 30 Gy IF-RT (HD8 trial); 532 patients in each treatment arm were eligible.

RESULTS

At 10 years, no arm differences were revealed with respect to freedom from treatment failure (FFTF) (79.8% versus 79.7%), progression-free survival (79.8% versus 80.0%), and overall survival (86.4% versus 87.3%). Non-inferiority of IF-RT was demonstrated for the primary end point FFTF (95% confidence interval for hazard ratio 0.72-1.25). Elderly patients had a poorer outcome when treated with EF-RT. So far, 15.0% of patients in arm A and 12.2% in arm B died, mostly due to secondary malignancies (5.3% versus 3.4%) or HL (3.2% versus 3.4%). After EF-RT, there were more secondary malignancies overall (58 versus 45), especially acute myeloid leukemias (11 versus 4).

CONCLUSION

Radiotherapy intensity reduction to IF-RT does not result in poorer long-term outcome but is associated with less acute toxicity and might be associated with less secondary malignancies.