Pediatric lymphocyte-predominant Hodgkin lymphoma: Review of Spanish patients between November-2007 and October-2019

Introduction From 2007 SEHOP Hodgkin Lymphoma Working Group decided to recommend pediatric patients(p) diagnosed with lymphocyte-predominant Hodgkin lymphoma (LPHL) were treated according to Euronet-PHL-LP1 for stage IA and IIA and according to updated international strategies for advanced stages. From 2008 pathology central review was encouraged taking advantage of the Euronet-C1 trial pathology reviewers. Objective: Collect and review outcome of pediatric p withLPHL diagnosed in Spain 2007–2019.

Methods Questionnaire was sent to 36 Pediatric Onco-Hematology Units. Descriptive analysis was performed: sex distribution, mean age at diagnosis, pathology central review, PET, stage, treatment, median follow-up, outcome and relapse treatment.

Results 28 out of 36 Pediatric Onco-Hematology Units responded the questionnaire:52p from 26 hospitals with LPHL were collected. Gender distribution:34 male/18 female(1.88/1). Mean age at diagnosis: 10 years(yrs) and 6 months(m)(5-16yrs). Centralized pathological review was performed in 61,5%. PET was used for staging in 80,7%. Stage distribution: IA 18p,IIA 22p,IIB 1p,IIIA 6p,IV 5p. Most frequent location: Cervical.

Treatment:15/18p stage I underwent surgery alone;11/22p stage IIA received 3 CVP and 5/22 3 R-CVP,2/22 combination of CVP and R-CVP,4/22 received polichemotherapy. Advanced stages were treated according to Euronet-C1 or LH-2003 trials or with R-CHOP.

Outcome: Median follow up 49m(range 3m-132m).13/52p (25%) relapsed with median relapse time of 9m(5m-52m).Stage I:5/15p(33,3%) treated with surgery alone relapsed,median 7m(range 5-9m),IIA: 4,III: 2 and IV 2p. Treatment: stage I polychemotherapy (CVP,R-CVP) IIA-IV:IEP/ABVD/ICE +rituximab + radiotherapy: 1IV. 4p underwent TPH.All 52p p are alive: 38p in 1^st complete remission(CR),12 in 2^nd CR,1 in PR still on chemotherapy,1 in 3^rd CR after R-CHOP and radiotherapy.

Conclusion In our series,Spanish p with LPHL have an excellent prognosis. Increasing centralized pathology review along last decade has been a major achievement to improve the quality of pathology diagnosis. Surgery alone was effective treatment for 66% of stage I p. 79% of p treated with low intensity chemotherapy or polychemotherapy + rituximab remain in 1st CR. Relapsed p can be safely rescued with low intensity chemotherapy and polychemotherapy +rituximab + radiotherapy. Unified international recommendations, participation in international multicenter trials and central pathology review will continue to be encouraged for Spanish pediatric p with LPHL along next years.