High-Risk, Advanced-Stage Hodgkin Lymphoma: The Impact of Combined Escalated BEACOPP and ABVD Treatment in Patients Who Rapidly Achieve Metabolic Complete Remission on Interim FDG-PET/CT Scan

PET-adapted therapy for advanced Hodgkin lymphoma - systematic review

INTRODUCTION

Positron emission tomography-computed tomography (PET-CT) performed after two chemotherapy cycles (PET-2) has become an accepted prognostic tool in Hodgkin lymphoma (HL). We evaluated the effect of PET-adapted strategy on outcome in advanced stage HL.

METHODS

In August 2017, we searched electronic databases, conference proceedings and ongoing trials. We included all studies in which treatment modification for advanced HL was performed based on the results of the interim PET scan. The primary analysis included randomized controlled trials (RCTs). Outcomes were progression-free survival (PFS) and overall survival (OS).

RESULTS

We identified 13 studies (4 RCTs, 7 phase II and 2 retrospective studies), conducted between 1999 and 2014, including 6856 patients. Of the four RCTS: one used therapy escalation, one did de-escalation and two trials performed both. Outcomes were assessed at different time point between 2 and 5 years. Three RCTs for de-escalating therapy, obtained similar outcomes despite reducing therapy, with a 2-year PFS of 88-92% (6 escalated BEACOPP (EB) vs. 4 ABVD cycles), a 5-year PFS of 91-92% (6/8 EB vs. 4 EB cycles) and a 5-year PFS of 80-82% (6 ABVD vs. omitting bleomycin after two successful ABVD cycles). Two RCTs implemented escalation. The randomization was between adding rituximab or not. In both trials, it did not affect outcome, with a 4-year PFS of 68-69% (addition of rituximab to BEACOPP after 2 ABVD cycles) and 5-year PFS of 88-90% (addition of rituximab to EB after 2 EB cycles). Performing true randomization between PET-adapted and a standard ABVD control arm was not feasible, given historical data.

CONCLUSIONS

This systematic review of PET-adapted therapy, mainly based on RCTs, suggests that a change to the treatment paradigm is appropriate in advanced HL.

An evidence-based review on the value of interim FDG-PET in assessing response to therapy in lymphoma

Assessing response to therapy in lymphoma is important for determining patients' prognosis, guiding subsequent treatment, and may be used as an outcome measure of prognostic and therapeutic trials. Traditionally, computed tomography was the mainstay for response assessment and was predominantly performed at the end of treatment, whereas the most recent guidelines propose ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) for this purpose. However, the value of FDG-PET performed during treatment (interim FDG-PET) is still a topic of debate. The purpose of this scientific communication is to provide an evidence-based overview of the value of interim FDG-PET in patients with lymphoma. The article first describes the development of imaging-based response assessment in lymphoma, the rationale and limitations of using FDG-PET for this purpose, and continues with the evidence-based clinical utility of interim FDG-PET in three major lymphoma subtypes (Hodgkin lymphoma, diffuse large B-cell lymphoma, and follicular lymphoma), and finishes with conclusions and recommendations for standard care and future research.

Frontline Therapy for Classical Hodgkin Lymphoma by Stage and Prognostic Factors

Hodgkin lymphoma is a highly curable malignancy in early and advanced stages. Most patients are diagnosed in their teens or twenties and are expected to live decades beyond their treatment. Therefore, the toxicity of treatment must be balanced with the goal of cure. Thus, treatment has been refined through prognostic models and positron emission tomography-computed tomography (PET-CT)-directed therapy. Stratification by prognostic models defines groups of patients with favorable characteristics who may be treated with less intensive therapy upfront, including fewer cycles of chemotherapy, lower doses of radiation, or omission of radiation altogether. Alternatively, high-risk patients may be assigned to a more aggressive initial approach. The modern use of interim PET-CT allows further tailoring of treatment by response.

Controversies on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma

Hodgkin lymphoma, even in advanced-stage, is a highly curable malignancy, but treatment is associated with short-term toxicity and long-term side effects. Early predictive markers are required to identify those patients who do not require the full-length standard therapy (and thus qualify for therapy de-escalation) and those patients who will not be cured by standard therapy (and thus qualify for therapy escalation). Multiple trials have assessed the value of ¹⁸ F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) after a few cycles of chemotherapy (also known as 'interim FDG-PET') in predicting outcome in advanced-stage Hodgkin lymphoma. Furthermore, multiple interim FDG-PET-adapted trials, in which patients with positive interim FDG-PET scans are assigned to escalated therapies, and patients with negative interim FDG-PET scans are assigned to de-escalated therapies, have recently been published or are currently ongoing, with generally heterogeneous results. The present article reports the currently available evidence (and controversies) on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma in patients with positive and negative interim FDG-PET findings following continuation of standard chemotherapy or escalated/de-escalated therapy.

Comparison of the efficiency of ABVD versus BEACOPP for Hodgkin lymphoma treatment: a meta-analysis

To compare the efficiency of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) against that of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) for treating Hodgkin lymphoma (HL). An extensive English-language literature retrieval on clinical outcomes after treatment by ABVD versus BEACOPP was conducted on Medline, PubMed, and Embase through the period ending December 2015. Odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was pooled based on the heterogeneity across individual studies. In total, seven articles reporting on four trials were included in this meta-analysis. Patients assigned to BEACOPP therapy had a better complete remission (CR) rate (OR = 0.55, 95 % CI 0.35, 0.87), overall survival (OS) greater than 5 years (OR = 0.64, 95 % CI 0.51, 0.81), and progression-free survival (PFS, OR = 0.56, 95 % CI 0.38, 0.81) than patients assigned to ABVD therapy. Subgroup analysis stratified using a different strategy showed no significant difference for OS between short courses of escalated BEACOPP combined with standard BEACOPP and that for ABVD (OR = 0. 72, 95 % CI 0. 45, 1.15). Reduced progression/relapse, better CR, and similar OS were observed with BEACOPP, indicating its superior efficiency of BEACOPP in the treatment of HL. However, more analysis of treatment-related toxicity is needed.

Risk-Adapted Treatment of Advanced Hodgkin Lymphoma With PET-CT

Although patients with advanced-stage classic Hodgkin lymphoma have excellent outcomes with contemporary therapy, the outcomes of patients with refractory disease is suboptimal. Identification of these high-risk patients at diagnosis is challenging as the differences in outcomes using clinical criteria are less marked using current modern therapy. Data suggest that an interim PET-CT may be a powerful tool in risk-stratifying patients. Retrospective studies show that a negative interim PET-CT after two to four cycles of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) is predictive of favorable outcome independent of IPS score. Currently, there are several ongoing trials that aim to determine whether early-response assessment can be used to select patients who might benefit from modifications of subsequent therapy, either by intensifying or abbreviating regimens and/or omitting radiotherapy with promising early results. Longer follow-up is required to assess whether this strategy impacts overall survival (OS). Herein, we review the results of recent trials using interim PET-CT-based adaptive design in the treatment of advanced HL.