Evaluating Management of Extra-Abdominal Desmoid Fibromatosis: A Retrospective Analysis of Treatments, Outcomes and Recurrence Patterns.

Desmoid fibromatosis (DF) is a rare, locally aggressive soft tissue tumour with unpredictable clinical behaviour. Historically, treatment has involved surgery; however, contemporary guidelines, such as those from the Desmoid Tumour Working Group, advocate active surveillance. This article reviews current perspectives on DF, focusing on epidemiology, pathogenesis, treatment strategies, emerging research directions and cost effectiveness based on our experience at the West of Scotland Musculoskeletal Oncology Service, Glasgow Royal Infirmary (GRI). We reviewed 101 patients diagnosed with desmoid fibromatosis between 2010 and 2024. A review of patient records was conducted to gather information on demographics, date of diagnosis, prior treatment, treatment initiation, intervention types, imaging intervals, follow-up duration, recurrence rate for surgery and other intervention, and discharge timelines. All data was systematically organized and analyzed to assess our outcomes. Out of 101 patients with DF in the study, 66% were females. The most common site of primary tumour was lower extremity (39.6%) followed by near equal distribution in upper extremity and trunk. Out of the total cases, 72 (71.2%) were successfully managed with active surveillance involving serial imaging and clinical reviews in accordance with European guidelines. A total of 22 patients (21%) received treatment: 10 underwent surgery alone, 2 had surgery combined with radiotherapy, 8 received only radiotherapy, 1 was treated with hormonal therapy and 1 participated in a trial with Nirogacestat. Of the seven remaining patients, six had unplanned surgery outside followed by active surveillance at GRI. One patient was on alternative treatment modality, homeopathy. The average number of MRI scans per patient was 3.11, with many patients requiring significantly more imaging. MRI surveillance varies significantly in desmoid tumours due to their heterogeneous behaviour. Active or symptomatic tumours often require more frequent scans (every 3-6 months), while stable cases may need only imaging annually or just clinical monitoring. Recurrence was noted in eight patients, all of which were related to prior surgery. The total combined cost of imaging and appointments exceeds £6500 per patient in active surveillance. We conclude that most patients with desmoid fibromatosis in our cohort were effectively treated with active surveillance, consistent with current European guidelines. Surgical management of desmoid fibromatosis in our cohort is historic and has shown a significant recurrence risk. Our study proposes a revised follow-up protocol that significantly reduces costs without compromising on patient care. We suggest a two-year surveillance period for stable disease with patient-initiated return to reduce unnecessary clinic visits, imaging and healthcare costs.