Most patients with Hodgkin lymphoma (formerly called Hodgkin's disease) will attain a remission after induction chemotherapy with or without radiation therapy. However, relapse rates range from 10 to 20 percent in favorable prognosis stage I-II disease  to 30 to 40 percent in patients with more advanced disease [2-6]. In addition, approximately 10 to 15 percent of patients experience progression of disease after a partial initial response.
Salvage therapy with second (or third) line regimens can achieve responses in approximately 50 percent of these patients, although long-term disease-free survival following the treatment of relapse with chemotherapy alone is unusual. Selected patients with poor prognosis after first relapse, patients with a second relapse, and patients with progressive disease are candidates for high dose chemotherapy followed by hematopoietic cell transplantation. (See "Hematopoietic cell transplantation in classical Hodgkin lymphoma" and "Second and third line chemotherapy regimens and biologic therapy for relapsing or resistant classical Hodgkin lymphoma".)
In this discussion, the following definitions will apply:
- Relapse (or recurrence) is the reappearance of disease in sites of prior disease and/or in new sites after initial therapy and attainment of complete response (CR).
- Progression refers to increasing evidence of disease after achieving a stable partial remission.
- Refractory disease is a failure to achieve a complete or partial response. The refractoriness can be primary (failure to respond to initial therapy) or secondary (initial response but failure to respond after disease relapse).
The vast majority of relapses from complete remission or induction failure will be in the setting of combination chemotherapy with or without complementary radiation therapy. Approximately 30 to 40 percent of patients with advanced Hodgkin lymphoma (unfavorable, stages IIB-IV) will have relapsed and/or refractory disease after initial chemotherapy [7-9]. Of these, 32 to 38 percent will have failed induction therapy (resistant disease), 27 to 38 percent will have relapsed less than 12 months after having obtained a CR, and 24 to 40 percent will have relapsed more than one year after attaining a CR. In almost all series, the latter is the most favorable for successful salvage.