Purpose: To identify poor prognostic factors in early-stage Hodgkin's disease that predict a high rate of relapse after radiotherapy alone.
Materials and methods: A total of 153 patients with stages I and II supradiaphragmatic Hodgkin's disease, treated between 1964 and 1986 with either radiotherapy alone (120 patients) or combined modality therapy (33 patients), were studied retrospectively to determine factors affecting freedom from relapse and absolute survival. Median follow-up was 13 years. Clinical factors were assessed by the stepwise use of a stratified log-rank test and included maximum tumor dimension in any site (< or = 6 cm or > 6 cm), age (< or = 40 or > 40), presence or absence of B symptoms, pathologic and clinical stages (I or II), number of sites involved (< or = 4 or > 4), gender, histologic subtype, and large mediastinal mass (none, small [< or = 6 cm], large [> 6 cm]).
Results: The only factors independently predicting a high rate of relapse were tumor dimension (> 6 cm) and number of sites (> 4 sites). At 10 years, in patients with and without the two poor prognostic factors treated with radiotherapy alone, the freedom from relapse rates were 53% and 84% (p < .0001) and the absolute survival rates were 72% and 85% (p = .004), respectively. Combined modality therapy significantly improved freedom from relapse, but not absolute survival, in patients with one or both poor prognostic factors.
Conclusions: Two poor prognostic factors were identified that were highly significant in predicting a high risk of relapse after radiotherapy alone. The addition of three cycles of chemotherapy to standard radiotherapy significantly reduced the relapse rate in high-risk patients.