Outcome Of Hematopoietic Cell Transplantation (HCT) In Pediatric Patients With Hodgkin Lymphoma (HL): Single Institution Results From Saudi Arabia

Most pediatric patients with Hodgkin lymphoma are cured of their disease with standard combined-modality first-line therapy. Those who relapse are subjected to salvage chemo-radiotherapy, and patients who respond often undergo either autologous or allogeneic HCT, with a reported outcome ranging from 40%-60%. Variables affecting the outcome of such patients are not clearly defined.

This study retrospectively reviewed the clinical characteristics and outcome of patients who underwent HCT at our institution.

Between 1995 and 2012, 29 pediatric (age <14 years) patients with HL underwent HCT. This cohort included 24 boys and 5 girls. Their median ages at initial diagnosis and at HCT were 9.85 years (mean 8.85; range 3.6-13.75) and 12.18 years (mean 11.24; range 5.6-14.9), respectively. 28 patients had classic HL (23 nodular sclerosis, 3 mixed cellularity, 1 lymphocyte-depleted, and 1 lymphocyte-rich) and one patient had nodular lymphocyte-predominance HL. Ten had persistent/progressive disease following first line therapy, while 19 had relapsed following achievement of complete response (CR). For these patients median time to relapse from completion of first-line therapy was 16.9 months (mean 20.1; range 1.9-53.1). All patients received salvage chemotherapy and/or radiotherapy prior to HCT; fifteen patients achieved CR, 13 had a partial response and one had progressive disease. Two patients had allogeneic bone marrow (BM) grafts from matched-related donors, while the rest had autologous grafts (16 BM; 10 PBSC; 1 BM+PBSC) following chemotherapy-based myeloablative conditioning. Twelve patients have relapsed/progressed post-HCT at a median of 6.04 months (mean 11.8; range 1.02-71.4). Nine patients have died; eight because of disease progression and one due to sepsis post HCT. Only two patients died within the first 100 days post HCT, giving a Day-100 mortality rate of 6.8%. Two patients who relapsed after HCT were salvaged with chemo/radiotherapy and remain disease free 2.8 and 9.7 years later. The 5-year estimated overall survival (OS) from HCT for the whole cohort is 61.6%, with an event free survival (EFS) of 57.9%. Patients who had persistent/progressive disease at the end first-line therapy or relapsed <6months off therapy had a worse OS and EFS as compared to those who relapsed later (OS 42.9% v. 75.3%, p=0.047 [Taron-Ware]; EFS 41.7% v. 60.8%, p=0.052 [Taron-Ware]).

The outcome of patients with relapsed/refractory HL following HCT is encouraging, as a majority of patients survive free of their lymphoma. Timing of relapse/progression remains an important prognostic factor and patients who fail early may be considered for novel therapeutic approaches.