The Health-Related Quality of Life of German Desmoid Patients: Results from the PROSa-DES and PROSa Study.

Desmoid-type fibromatosis (DT) is a rare, locally aggressive soft tissue tumor with a frequently chronic course and substantial impact on health-related quality of life (HRQoL). While international studies have demonstrated considerable symptom burden and psychosocial impairment, data from Germany are lacking. This study aimed to assess HRQoL in German patients and to identify factors associated with HRQoL. In this cross-sectional analysis, adult patients with histologically confirmed DT completed the EORTC QLQ-C30 and the disease-specific Desmoid-Type Fibromatosis Quality of Life Questionnaire (DTF-QoL). HRQoL scores were compared with reference data from the German general population, German sarcoma patients, and international DT cohorts. Sociodemographic, disease-, tumor-, and treatment-related factors associated with HRQoL were examined using multivariate linear regression analyses. A total of 155 patients were included (69.7% female; mean age 45.0 years). Compared with the German general population, DT patients reported clinically relevant impairments in role, social, and emotional functioning and higher symptom burden, particularly pain, fatigue, and insomnia. Compared with sarcoma patients, DT patients showed better physical, role, and social functioning, while emotional functioning and symptom burden were largely comparable. German DT patients reported consistently worse HRQoL than Dutch/UK cohorts and moderately worse outcomes than Indian cohorts. Female gender, unemployment or disability pension, intensive multimodal treatment, multiple lines of systemic therapy, and tumor location in the lower extremities were independently associated with poorer HRQoL. DT is associated with sustained and clinically meaningful HRQoL impairment. HRQoL is driven primarily by psychosocial and treatment-related factors rather than disease duration, supporting the concept of DT as a chronic condition requiring long-term, multidisciplinary supportive care.