Quality of life and tumor location in patients with desmoid tumors: Data from the desmoid tumor research foundation natural history study.

e18291 Background: Desmoid tumors (DTs) are sarcoma, known to invade surrounding tissues, compromising organ function and complications. As few as 5 per 1 million people are diagnosed with DTs annually, which may be an underestimate of the actual affected population due to difficulty in correctly diagnosing the disease. To improve awareness of DTs and better inform treatment development, DTRF, in partnership with the NORD, launched the DTRF patient registry and natural history study. Here, we describe patient demographics, tumor location, and QOL in registry patients. Methods: The registry launched September 2017 and contains 15 surveys covering diagnostics, disease, treatment, care management, and quality of life. As of January 2019, 357 patients have completed 2,371 surveys. Results: Registry participants are mostly white (88%, 313/357), female (81%, 277/343), and reside in 27 countries with 80% (285/357) US-based. Median age at diagnosis is 33 and the time from onset of symptoms to diagnosis was more than 1 year for 54% (189/352). DT location was reported for 119 respondents at time of data collection. Most prevalent locations were joint /extremities (39%, 47/119), intra-abdominal (24%, 28/119), and chest wall (24%, 29/119). Multiple locations were indicated for 22% (26/119). QOL reported as very good or excellent ranged from 28% to 60%, depending on DT location. Conclusions: Patients with DTs have varied QOL and tumor locations. Data collection through the study is ongoing. [Table: see text]