Risk-adapted therapy for clinical stage I-II Hodgkin's disease: 7-year results of radiotherapy alone for low-risk disease, and ABVD and radiotherapy for high-risk disease

Treatment outcomes were documented for 204 adult patients with clinical Sta ge I-Il Hodgkin's disease who were treated with risk-adapted ABVD (doxorubi cin, bleomycin, vinblastine and dacarbazine) and radiotherapy (RT) at the T oronto-Sunnybrook Regional Cancer Centre between 1984 and 1994. Forty-nine patients with clinical Stage I disease (excluding bulky mediastinal present ations) and 50 patients with a combination of clinical Stage IIA disease, a ge 50 years or less, and favourable pathology (lymphocyte predominant or no dular sclerosing histology) were identified as low risk and treated with RT alone to 35 Gy. One hundred and five high-risk patients were treated with chemotherapy (86 with ABVD) followed by RT to 25 Gy. The 7-year cause-speci fic, overall and disease-free survivals were 95%, 90% and 75% respectively for the low-risk cohort, and 91%, 90% and 88% respectively for the high-ris k cohort. In-field relapses accounted for 50% of the failures in both group s. Sixteen of 24 (67%) patients with RT failure and 6/14 (43%) with combine d modality therapy (CMT) failure were salvaged. Twenty-eight per cent of th e patients treated with RT and 21% of those treated with CMT developed hypo thyroidism by 7 years. Fatal complications were recorded in 6% of the low-r isk patients managed with RT and 8% of high-risk patients managed with CMT. Septic death and second malignancy accounted for the majority of treatment -related fatalities. Risk-adapted therapy emphasizing RT alone for selected patients with favourable prognostic factors and CMT based on ABVD provides excellent long-term disease control. Further treatment refinements, includ ing the wider application of CMT with lower doses of chemotherapy and RT, w ill be required to reduce the rate of fatal complications to more acceptabl e levels.