High response rate to combined chemotherapy avoiding radiotherapy in children and adolescents with classical Hodgkin lymphoma. Preliminary results of GALOP LH 2017 Protocol

Introduction Children with diagnosis of Hodgkin Lymphoma (HL) have achieved high rate of survival, and for this reason the aim of our current study is to decrease radiotherapy (RT) indications for avoiding late sequelae. To analyze disease response rate to combined chemotherapy in children and adolescents with classical HL included in LH GALOP 2017 Protocol.

Methods From Sept 17 to Oct 19, 45 consecutive pediatric patients with HL were registered in LH GALOP 2017 Protocol. This is a non-randomized, multicenter, prospective pediatric HL treatment trial, stratified according to initial risk factors and response to chemotherapy (interim and late response), with reduced cumulative doses of antineoplastic agents and avoiding radiotherapy in good responders. Chemotherapy is based on ABVD and ESHAP regimes. No radiotherapy is delivered when complete response is achieved after chemotherapy in any risk groups. Patients who achieved partial response receive low dose (30Gy) involved node RT. Stable or progressive disease is assumed as a trial failure at any moment. (Further information ClinTrials.gov NCT NCT03500133

Results Forty-three of 45 patients (pts) were eligible for analysis. Misdiagnosis (1pt), additional radiotherapy off protocol (1pt). Males: 22pts Females: 21pts. Median age: 11.3 (range: 4.7–16.2) years. Median follow-up was: 10 months. Bulky mediastine: 14pts (32.5%),B-symptoms: 20pts (44.4%), extranodal invasion: 2pts (4.2%), systemic involvement: 17pts (39.5%), lung: 7pts (16.2%), liver: 4pts (9.3%), bone: 3pts (6.9%), bone marrow: 3pts (6.9%).Histology subtyping: Nodular Sclerosis: 34pts (79%), Mixed Cellularity: 5pts (11.6%), LR CHL: 4pts (9.3%). Autoimmune related initial disorders: 4 pts (9.3%). Initial staging: IA: 4pts, IIA: 11pts, IIB: 6pts, IIIA: 6pts, IIIB: 4pts, IVA: 2pts, IVB: 10pts. Initial risk assignment: Low: 8pts (18.6%), Intermediate: 15pts (34.8%), High: 20pts (46.5%). Early response assessment: CR: 23/42pts (54.7%). Late response assessment: CR: 32/34pts (94.1%)PD: 1pt, PR: 1pt. RT: 2 pts (5.8%). Acute therapy related toxicity was mild-moderate, mainly hematological. No relapses and deaths were observed.

Conclusion High rates of complete responders were found in the interim assessment and at the end of chemotherapy, even with high proportion of advanced disease, achieving a better treatment tailoring and avoiding RT in most of cases. At 10 months of median follow-up only one case of refractory disease was found as trial failure event for survival analysis.