Background Desmoid fibromatosis (DF) is a rare fibroblastic proliferation that was historically treated with surgery. We report (a) outcomes using low‐dose chemotherapy, methotrexate (MTX), and vinorelbine (VNL) for patients with progressing disease (PD) and (b) whether tumor volume ( V tumor ) and T2 signal on magnetic resonance imaging (MRI) are more reflective of treatment response compared with maximum tumor dimension ( D max ) defined by RECIST1.1. Methods Patients with biopsy‐proven DF, treated with MTX/VNL from 1997 to 2015 were reviewed. MRI for a subset of patients was independently re‐evaluated for response by RECIST, V tumor , and quantitative T2 hyperintensity. Results Among 48 patients treated for a median 19 months MTX/VNL, only nine (19%) had previous surgery. RECIST‐based overall response rate was complete response (CR) 20 (42%) + partial response (PR) 19 (39%), stable disease (SD) 8 (17%), for a clinical benefit rate of 98%. The median progression‐free survival (PFS) was 120 months, (95%CI 84‐155 months). Thirty‐six (75%) patients had not progressed at a median 38 months from treatment completion. Most common grade 1/2 toxicities included nausea (n = 12, 25%) and fatigue (n = 9,19%) with no grade 3/4 toxicities. In 22 patients with serial MRIs, there was a decrease in D max mean by 30%, V tumor by 76%, and in 19/22 (86%) a decrease in T2 signal intensity. Conclusion Low‐dose MTX/VNL for a defined duration has high efficacy with sustained benefit and minimal toxicity for treating DF. V tumor and T2 signal might better predict treatment response than RECIST.

Objective: Clinical experience suggests a high prevalence of emotional distress in patients with desmoid tumor (DT). We examine longitudinal Distress Assessment and Response Tool (DART) scores to estimate prevalence and persistence of distress, and compare cross-sectional data between DT and malignant sarcoma cohorts, to identify predictors of distress. Methods: Patients with DT completed DART at: T1-diagnosis, T2-during, T3-<6 months, and T4-≥6 months, post-treatment. DART includes patient-reported outcome measures of physical symptoms (ESAS-r), depression (PHQ-9), anxiety (GAD-7), and social difficulties (SDI-21). Descriptive prevalence and persistence of anxiety, depression, and wellbeing are reported, and mixed model regression analyses determine predictors of distress. Results: Between 2012 and 2018, a total of 152 DART screens from 94 patients with DT were completed (T1: n = 44, T2: n = 31, T3: n = 22, T4: n = 55). Patients had a mean age 40 years, 78% were female and DT locations were abdominal wall (48%), extremity (30%), and mesentery (22%). Moderate to severe ESAS-r scores (≥4) persisted at T4 for anxiety (20%), depression (13%), and poor wellbeing (31%). Compared to 402 patients with malignant sarcoma, patients with abdominal wall sited DT reported severe PHQ-9 and GAD-7 scores twice as frequently. Abdominal wall location, female sex, history of mood problems, and psychosocial concerns were significant predictors of anxiety, depression, and poor wellbeing in DT. Conclusions: Adults with DT experience persistently high emotional distress compared to patients with malignant sarcoma. Women with abdominal wall DT, prior mood, and current psychosocial concerns need early attention within multidisciplinary treatment settings to reduce persistent distress. K E Y W O R D S aggressive fibromatosis, cancer, desmoid tumor, Edmonton Symptom Assessment Scalerevised (ESAS-r), emotional distress, oncology, psychological distress, quality of life (QOL), sarcoma supportive careThe last two authors contributed equally to this article and share last authorship.