Surgical Resection Alone in Children with Limited Stage Lymphocyte Predominant Hodgkin’s Lymphoma - The Experience of the EuroNet-PHL Group.

Introduction: Lymphocyte predominant Hodgkin’s lymphoma (LP) is a rare CD20-positive subtype of Hodgkin’s lymphoma which was only recently recognised as a separate disease entity. Most patients present with localised stage IA or IIA disease and usually, the disease has a relatively indolent clinical course. Up until recently, children with LP were treated alike classical Hodgkin’s lymphoma and received chemotherapy +/− radiotherapy. Two published reports of surgical resection alone in 19 children with LP (Pellegrino 2003, Murphy 2003) suggest that this may be an effective therapeutic option for a select group of children with limited stage disease. Study objectives: Can a proportion of children with limited LP be cured by surgery alone if resection is complete? Is a watch and wait strategy after surgery alone safe for those patients with residual disease after resection? What is the risk of relevant upstaging at relapse and of transformation into an aggressive B-cell lymphoma?

Methods: European study groups participating in the EuroNet-PHL inter-group were requested to report their experience of surgery alone in children with LP. Surgery as single treatment modality has been used on a case by case basis for several years by the SFCE (France), the DAL / GPOH (Germany), and more recently by the UKCCSG (UK). Individual data of 57 patients were collected using a common CRF. 11 cases already published by Pellegrino were updated and are included.

Results: 49 patients with initial stage IA achieved a CR after surgery. In 8 patients (5 in IA, 1 in IIA, 2 in IIIA) resection was incomplete. At a median observation time of 43 months (max. 172 months) all patients are alive. In the CR group 13 relapses were observed, all occurring early within 26 months of resection. Freedom from progression is estimated to be 67% (95% CI [59%; 75%]). Of the 8 patients who had incomplete resection 6 patients relapsed (p=0.008), of whom one (initial stage IIIA) relapsed as non-Hodgkin lymphoma. Of the 16 stage IA patients who experienced a relapse, 9 had a local relapse alone and the remaining 7 relapsed with stage II A. The rate of upstaging (B-symptoms or relapse stage > II) was 0% (95%-CI: [0%; 21%]).

Conclusion: If complete resection is achieved, a substantial proportion (about 2/3 in our series) of surgically treated stage IA patients experience long-term remission and may be actually cured. Nevertheless, as most of the relapses occurred in the initially involved lymph node region, a better evaluation of the remission status after surgery may be obtained if FDG-PET is combined with CT/MRI. Based on these data we have designed a Europe-wide study in FDG-PET-negative stage IA-IIA LP to prospectively confirm these promising results in a larger cohort.