The Desmoid Tumor Research Foundation

July 2025

Desmoid-Type Fibromatosis Tumors in Children After First-Line Failure: Clinical Aspects and Approaches for Subsequent Therapeutic Lines

Author Information

Anna Borovkov 1 2, Daniel Orbach 1, Jacinthe Bonneau-Lagacherie 3, Lina Carausu 4, Grégory Guimard 5, Stéphanie Haouy 6, Sarah Jannier 7, Anne Pagnier 8, Stéphanie Proust 9, Cécile Verite 10, Marie Pierre Castex 11, Yves Reguerre 12, Pascale Blouin 13, Ludovic Mansuy 14, Lucy Métayer 15, Nadège Corradini 16, Anne Sophie Defachelles 17, Hélène Boutroux 1

1SIREDO Oncology Center (CareInnovation and Research for ChildrenAdolescents and Young Adults with cancer)Institut Curie, PSL University, Paris, France. 2SIREDO Oncology Center (Care, Innovation and Research for Children, Adolescents and Young Adults with cancer), Institut Curie, PSL University, Paris, France. 3Pediatric Oncology and Hematology Department, University Hospital of Rennes, Rennes, France. 4Pediatric Oncology and Hematology Department, University Hospital Center of Brest, Brest, France. 5Pediatric Oncology and Hematology Department, University Hospital Center of Reims, Reims, France. 6Pediatric Oncology and Hematology Department, University Hospital Center of Montpellier, Montpellier, France. 7Pediatric Oncology and Hematology Department, Hautepierre Hospital, Strasbourg, France. 8Pediatric Oncology Department, University Hospital Center of Grenoble, Grenoble, France. 9Pediatric Oncology and Hematology Department, University Hospital Center of Angers, Angers, France. 10Department of Pediatric Hematology, Bordeaux Hospital, Bordeaux, France. 11Pediatric Oncology and Hematology Department, Hôpital des Enfants, University Hospital Center of Toulouse, Toulouse, France. 12Pediatric Oncology and Hematology Unit, University Hospital Center of Saint Denis de la Réunion, Bellepierre, France. 13Pediatric Oncology and Hematology Department, University Hospital Center of Clocheville, Tours, France. 14Pediatric Oncology and Hematology Department, University Hospital Center of Nancy, Nancy, France. 15Department of Oncology for Child and Adolescent, Gustave Roussy, Villejuif, France. 16Institut of Pediatric Hematology and Oncology (IHOPE), Leon Berard Center, Hospices Civils de Lyon, Lyon, France. 17Pediatric Oncology Unit, Oscar Lambret Center, Lille, France.

Publication

Pediatr Blood Cancer

Summary

Background: Desmoid-type fibromatosis (DTF) is a rare intermediate malignancy with high local aggressiveness and recurrence in children after first-line methotrexate-vinblastine (Mtx-Vbl) regimen. The objective is to describe refractory DTF to standardize second-line therapy. Methods: This national multicenter retrospective study included patients (<25 years) with progressive/refractory DTF after Mtx-Vbl first-line. The primary objective was to evaluate response rate (RR: complete/partial response [CR/PR]) and progression-free survival (PFS2) following second-line treatments. Secondary objectives included overall burden of therapy and predictive factors for therapeutic efficacy analysis. Results: From 2000 to 2022, 50 patients fulfilled inclusion criteria. Median age at first relapse was 15.6 years [range: 0.9-24.8]. Second-line treatments included exclusive medical treatment for 86%-majority alkaloid-based re-challenge (60%)-exclusive local therapy in 8%, both (4%) and observation (2%). RR to any medical therapy was 30% [95% CI: 16-44], specifically 35% [95% CI: 15-55] for alkaloid-based regimens with clinical benefit (CR/PR or stabilization) in 85%. The 5-year PFS2 was 44% [95% CI: 30-58]. Limb location was the only significant predictive factor for PFS2 (p < 0.01). Overall treatment load comprised a median of three lines [range: 2-8] over 27 months median duration [range: 4-90]. Local therapy was done for 50% of patients. One patient died from secondary digestive infection. Conclusions: Refractory DTF should be considered as a chronic disease with significant treatment burden where objectives should be regularly reassessed. Even for refractory disease, local therapy might be avoided in half of cases. Authors propose a second-line treatment algorithm for pediatric refractory DTF.

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