Desmoid Tumour FAP — SCE Medical Oncology MCQ

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HardSarcomaDesmoid Tumour FAPSCE Medical Oncology

A 50-year-old man with familial adenomatous polyposis (FAP) undergoes prophylactic colectomy at age 25. At age 50, he develops a large (8 cm) desmoid tumour in the mesentery causing ureteric obstruction. What systemic therapy options exist for progressive desmoid tumours in FAP?

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Correct answer: C — Sorafenib or gamma-secretase inhibitor (nirogacestat)

Desmoid tumours are a significant complication of FAP (occurring in approximately 10-20% of patients), often arising in the mesentery after abdominal surgery. For progressive/symptomatic desmoids, nirogacestat (gamma-secretase/Notch pathway inhibitor) demonstrated significant PFS benefit in the DeFi trial and has regulatory approval. Sorafenib showed activity in the DESMOID trial (Alliance A091105). Other options include low-dose methotrexate + vinblastine, tamoxifen and NSAIDs (sulindac/celecoxib). Surgery carries high recurrence risk for mesenteric desmoids.

Reference: ESMO 2024 Desmoid Tumour Guidelines; DeFi trial Gounder et al NEJM 2023; Alliance A091105