Long-term events in adult patients with clinical stage IA-IIA nonbulky Hodgkin's lymphoma treated with four cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine and adjuvant radiotherapy: a single-institution 15-year follow-up

Purpose: To report on long-term events after short doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy and adjuvant radiotherapy in favorable early-stage Hodgkin's lymphoma.
Experimental Design: We monitored late events and causes of death over 15 years (median follow-up, 120 months) in 120 patients with nonbulky stage IA-IIA Hodgkin's lymphoma, treated with four cycles of ABVD and limited radiotherapy. Pulmonary and cardiac function tests were done throughout the follow-up. Outcome measures included cause-specific mortality, standardized mortality ratio, and standardized incidence ratio for secondary neoplasia.
Results: Projected 15-year event-free and overall survival were 78% and 86%, and tumor mortality was 3%. Standardized mortality ratio was significantly higher than 1 for both males (2.8; P = 0.029) and females (9.4; P = 0.003). The risk of cardiovascular events at 5 and 12 years was 5.5% and 14%, with a median latent time of 67 months (range: 23-179 months) from the end of radiotherapy. Pulmonary toxicity developed in 8% of patients; all had received mediastinal irradiation and the median time from radiotherapy to pulmonary sequelae was 76 weeks (range: 50-123 weeks). The risk of secondary neoplasia at 5 and 12 years was 4% and 8%, respectively, with no cases of leukemia. Fertility was preserved.
Conclusions: Long-term events were mostly related to radiotherapy; the role of short ABVD chemotherapy was very limited, as documented by fertility preservation and lack of secondary myelodysplasia/leukemia. A proportion of patients died from causes unrelated to disease progression and the excess mortality risk was mostly due to the occurrence of secondary neoplasms and cardiovascular diseases. A moderate dose reduction of radiotherapy from 40-44 Gy to 30-36 Gy did not decrease the risk of late complications; abolishing radiotherapy in nonbulky early-stage Hodgkin's lymphoma is being evaluated.