(P 260) BURDEN OF ILLNESS OF DESMOID TUMORS

Objective: Aggressive fibromatosis, or desmoid tumor (DT), is a rare, locally aggressive, and invasive soft tissue tumor. DTs can infiltrate surrounding tissues and affect organs and nerves, and it behaves unpredictably, resulting in substantial clinical burden and negatively impacting quality of life in patients. Despite treatment, DTs have a high rate of recurrence (>70% in some cases). The present study provides a comprehensive literature review of the burden of illness of DTs.

Methods: Searches of PubMed, Embase, Cochrane, and key conferences were conducted in November 2021 to identify articles describing the burden (clinical and humanistic), epidemiology, costs, treatments, and treatment guidelines for DTs.

Results: A total of 541 publications were identified from the searches, and 68 were selected for inclusion in the evidence base for this review. Diagnosis of DTs is challenging because of its morphologic heterogeneity and variable clinical characteristics. Patients visit multiple healthcare providers, often facing delays in the correct diagnosis; up to 40% of DT cases can be misdiagnosed. The low global incidence of DTs (estimated 3 to 5 cases per year per million population) limits disease awareness. Patients with DTs experience a high symptom burden: up to 63% of patients suffer from chronic pain, which leads to sleep disturbance (73% of cases), irritability (46% of cases), and anxiety/depression (15% of cases). The most frequently mentioned symptoms in the Gounder/DTRF Desmoid Symptom Scale (GODDESS) patient-reported outcome questionnaire are disfigurement/altered appearance, nerve pain, decreased range of motion, fatigue, and nausea. Overall, the mean global health status (i.e., quality of life, as measured by the EORTC Core Quality of Life questionnaire) is lower than in healthy controls (average scores, 65.58 vs. 81.43; P < 0.0001, respectively). Patients indicate greater financial burden compared with healthy controls (based on self-reports, 26% of patients with DT stopped working and 10% switched to working part-time due to their disease); however, no published studies evaluating the direct or indirect costs of DTs were identified. Although no treatment approved by the US Food and Drug Administration currently exists for DTs, some of these tumors can be initially managed through active surveillance. Surgery, locoregional therapy, or systemic therapy, including chemotherapy and tyrosine kinase inhibitors, are treatment options for symptomatic or progressive disease or for preventing significant complications. The lack of approved treatments and robust clinical and quality of life data for DTs limits our understanding of the optimal management and treatment sequence.

Conclusion: The substantial burden of illness of DTs is related to the clinical and chronic symptoms (pain, physical, and functional limitations), decreased quality of life (due to anxiety and depression) and increased financial burden. There is a high unmet need for treatments that target DTs and are associated with improved quality of life for patients.