Early prediction of response to therapy: the clinical implications in Hodgkin’s and non-Hodgkin’s lymphoma

Excerpt

Both Hodgkin lymphoma (HL) and the aggressive non-Hodgkin’s lymphoma (NHL), particularly its most prevalent subtype, diffuse large B-cell lymphoma (DLBCL), are potentially curable diseases. Approximately 90% of patients with early-stage HL achieve a complete response (CR); however, the relapse rate can be as high as 35%, depending on the pretreatment risk factors. Despite a more predictable outcome with HL, the DLBCL is characterized by a markedly variable clinical course and a response profile with the prognosis determined by a host of clinical and biologic factors [1, 2]. Even though the proportion of DLBCL patients achieving a CR has increased with the emergence of recent therapeutic innovations, the median overall survival (OS) is still less than 5 years [3]. Despite substantial efforts to define clinically relevant prognostic factors, it has increasingly become more clear that existing risk stratifying systems do not adequately serve as robust means to individualize therapy. There is variability in outcome within the specific risk groups, particularly in intermediate risk DLBCL [4‐8]. For HL, the widely used international prognostic score took into account only those patients with advanced-stage disease and thus, not applicable in early-stage disease [4]. Additionally, both of the prognostic systems developed by The European Organization for Research and Treatment of Cancer and Groupe d’Etude des Lymphomes de l’Adulte (EORTC/GELA) and that created by the German Hodgkin Lymphoma Study Group (GHSG) are not based on a comprehensive multivariate analysis [5‐7]. Hence, there is a strong need for more effective prognostic surrogates to guide risk-adapted strategies to improve the outcome of lymphoma patients by counterbalancing risk with benefit. The use of [¹⁸F]fluorodeoxyglucose positron-emission tomography (FDG-PET) imaging and more recently integrated PET/CT systems not only has changed the definition of response in lymphoma but its use has also suggested a significant change in management. The crucial question remains “is there enough evidence and justification to adjust therapy based on FDG-PET findings at the time of interim restaging”. …