Risk‐Stratified and Response‐Adapted Therapy for Pediatric Hodgkin Lymphoma in Argentina: The GATLA Experience

<b>Background:</b> The international cooperation between GATLA and AHOPCA with the support of St. Jude led to the adoption of the OEPA/COPDAC as a strategy to improve outcomes in high risk (HR) patients with HL. This study also includes the ABVD regimen for intermediate risk (IR) and low risk (LR) patients. <b>Methods:</b> Patients were stratified by predefined risk assignment. HR was defined as a disease in stages II B, III B, and IV. Modality treatment: LR: ABVD × 4 ± IFRT (20 Gy); IR: ABVD × 6 ± IFRT (20 Gy); and HR: OEPA-COPDAC + IFRT (20/25 Gy). The staging and response were reviewed in a periodic discussion of presentation of cases in the group. Eligibility for radiotherapy: LR patients in partial response (PR) after 4 ABVD and IR patients in PR after 2 ABVD received IFRT. All HR patients received IFRT at 20 (complete response (CR)) or 25 Gy (PR) depending on the response achieved after the first two OEPA cycles. <b>Results:</b> From November 2012 to June 2022, 203 pediatric patients were enrolled. A total of 171 patients were eligible in this analysis. HR: 98 patients (57.3%), IR: 52 patients (30.4%), and LR: 21 patients (12.3%). More than half of the patients were in stages III and IV and more than half also presented B symptoms. The response evaluation was performed by PET/CT in 147/171 patients (86%). A total of 68/171 patients (40%) did not received radiotherapy. Radiotherapy was omitted in 95% of the LR patients and 70% of the IR patients. The 10-year OS was 95% (90.7-97.6) for the 171 patients and 93% (85.3-96.4) for HR patients. The 10-year EFS was 91% (85.2-94.2) for the 171 patients and 87.8% (79.5-92.9) for HR patients. <b>Conclusion:</b> The international cooperation made it possible to significantly improve the outcomes of patients with advance disease in Argentina compared with our previous experience (7-PHD-96: COPP-ABV × 6 + IFRT Bulky Disease or PR (20/25 Gy): 5yOS: 85%, 5yEFS: 67%), reduce the number of patients who required radiotherapy, and reproduce the European experience for HR patients in a totally different context.