Abstract
BACKGROUND: Desmoid tumors (DT) are rare, locally aggressive neoplasms that affect a young population and have a tendency for recurrence. There is sparse contemporary real-world data to guide practice for DT. Here, we report on a large cohort of DT patients, describing patterns of care and clinical outcomes. METHODS: Data on DT patients first seen between 2010 and 2021 were extracted from a prospective database and supplemented with a retrospective review of hospital records. Trends in treatment use were analyzed using the Cochran-Armitage test. Time-to-next intervention (TTNI) was estimated with the Kaplan-Meier method. Imaging response was categorized using the RECIST v1.1 criteria. RESULTS: A total of 135 patients, 265 treatment episodes were analyzed. Median follow-up was 4.3 years. The common tumor sites were abdominal wall (27%), upper limb (20%), lower limb (16%), and intra-abdominal (15%). Over time, the proportion of patients receiving no upfront treatment was stable (2010-2013: 31%, 2014-2017: 35%, 2018-2021: 29%; p = 0.5), but there was increasing first-line use of NSAID/tamoxifen (7%, 41%, 47%; p < 0.001), and decreasing first-line use of radiotherapy (35%, 14%, 4%; p < 0.001) and surgery (28%, 8%, 18%; p < 0.05). At 5 years, the proportion not requiring treatment switch was highest following surgery (72%), radiotherapy (66%), and no upfront therapy (52%). 12% and 5% of patients without treatment achieved partial and complete imaging responses at 2 years. CONCLUSION: We highlight the heterogeneity and trends in DT management over a 12-year period, affirming the role of active surveillance, radiotherapy, and surgery in selected patients. Medical therapies are evolving and may significantly influence the DT management paradigm.