Milea Timbergen

247 Introduction Sporadic desmoid-type fibromatosis (DTF) is a rare, borderline tumour of the soft tissues 1-3 . Most patients are females, aged between 20 and 40 years at primary diagnosis 3 . Sporadic DTF arises in musculoaponeurotic structures with the most common sites being the abdominal wall and the extremities 4 . Symptoms vary, depending on tumour site, size and infiltration of adjacent structures, resulting in pain and/or functional impairment. DTF does not metastasize, rarely has fatal outcomes, often displays long periods of spontaneous stabilisation, and can undergo spontaneous regression 5 . Surgical resection, radiotherapy, non-cytotoxic and cytotoxic systemic therapies may be considered in patients with symptomatic disease but unfortunately, these “traditional” treatment options do not guarantee tumour reduction and/or clinical response 6 . Local recurrence after surgery remains high 7, 8 , leading to a reduction in surgical treatments for DTF over recent decades 3, 4 . Additionally, “active” forms of treatment can be debilitating, causing greater morbidity than the tumour itself. For these reasons, active surveillance is now recommended as a first line management for most patients with DTF 6, 9 . Therefore, DTF has obtained a “chronic” status and its impact on patients should be evaluated accordingly. Health-related quality of life (HRQoL) provides information beyond traditional measures of efficacy in oncology such as overall survival, and is increasingly used as an endpoint in clinical trials 10, 11 . We previously performed a systematic literature review to evaluate which HRQoL-measures were used in research to assess HRQoL in DTF 12 . Generic HRQoL- measures (e.g., the cancer specific core questionnaire from European Organisation for Research and Treatment of Cancer; the EORTC quality of life core questionnaire (EORTC QLQ-C30)) may not consider disease-specific issues in DTF patients. Site-specific tools (e.g., Toronto Extremity Salvage Score), may not be relevant to certain groups (e.g., those with an abdominal wall, or head and neck tumours). At present, there is no validated DTF-specific HRQoL-tool, and this was illustrated by a systematic literature review published by our group 12, 13 . In order to gain greater insight into the issues that patients with DTF experience in their daily lives, and to evaluate their experiences of health care including the supportive care system, we previously organised focus groups and semi-structured interviews, in the United Kingdom (UK) and in the Netherlands (NL) 12, 13 . These studies identified issues covering various domains including the diagnostic pathway, the treatment pathway, daily limitations (e.g., physical and psychological symptoms), and experiences with the current health care system. 9