International panel releases recommendations for evidence-based treatment of desmoid tumors

Desmoid tumors are lesions in connective tissue that often occur in the extremities and tend to infiltrate locally. Recent advances in diagnosis and treatment have led to changes in the way these tumors are managed. An international panel has developed evidence-based treatment recommendations for desmoid tumors to help orthopaedic surgeons manage this patient population (Figure 1). Their findings were presented as a paper at the AAOS 2025 Annual Meeting by Benjamin Alman, MD, FAAOS, who is the James R. Urbaniak, MD, Distinguished Professor of Orthopaedic Surgery at Duke University School of Medicine.

Choosing appropriate treatment for patients with desmoid tumors can be challenging. Watchful waiting is often used in patients with asymptomatic disease because about 20% of tumors spontaneously regress. Resection is used less often due to mortality and relapse rates. Systemic therapies continue to evolve.

A group of 89 clinicians and researchers with expertise in desmoid tumors and leaders of patient advocacy groups were invited to participate in a panel to review the literature and develop evidence-based guidelines, and more than 60 actively participated, wrote Dr. Alman. They collected sources including a prior consensus paper and meta-analyses of new data when available. Subsequently, they used a modified Delphi process to develop their recommendations.

The panel determined that reliable diagnosis can be made with needle biopsy. They recommend mutational analysis of the CTNNB1 gene, which encodes beta-catenin, to confirm the diagnosis.

For cases that are negative for mutation, practitioners should consider genetic counseling or germ line APC mutational analysis, “as these patients may have a form of familial adenomatous polyposis, and routine colonoscopy is needed for surveillance,” Dr. Alman wrote.

The panel supports active surveillance as the first line of therapy, unless a desmoid tumor is causing significant symptoms or may cause death. The panel also confirmed that practitioners should avoid surgery, even in the smallest tumors. “Recurrence rates are quite high, and overall outcome, as shown in meta-analysis, is worse than without surgery,” Dr. Alman explained.

When a desmoid tumor is life-threatening and progressive, the panel recommends methotrexate plus vinblastine as first-line therapy. In addition, tyrosine kinase inhibitors can be considered in the case of progression despite first-line treatment. The panel noted that gamma secretase inhibitors are promising as second-line treatment, but they are associated with ovarian dysfunction and therefore should be used with caution in female patients.

Regarding radiation therapy, the panel noted that it is effective, although associated with side effects that should be avoided, especially in children. The panel also suggested the consideration of alternative modalities for local treatment, such as cryotherapy.

Dr. Alman was the sole author of “Evidence-based recommendations for treating desmoid tumors: consensus of the Desmoid Tumor Working Group.”

Keightley Amen, BA, ELS, is a freelance writer for AAOS Now.

Reference

1. Mangla A, Agarwal N, Schwartz G. Desmoid tumors: current perspective and treatment. Curr Treat Options Oncol. 2024;25(2):161-175. doi: 10.1007/s11864-024-01177-5