Milea Timbergen

162 Material and methods This study uses the PRISMA guidelines for reporting a systematic literature review. Information sources On December 19 th 2019, a systematic literature search was performed by an expert librarian. The search was updated on April 14 th which yielded one additional inclusion. Used databases include Embase.com, Ovid MEDLINE, Web of Science, Cochrane CENTRAL, PsychInfo Ovid and Google Scholar. Duplicated records were removed. Case reports were excluded and an English language filter was applied. There were no constrains on publication dates. Supplemental Materials 1 depicts the search strategy. Eligibility criteria Studies with sporadic DTF as a main subject and full-text availability were included by two researchers (MJMT, AWS). Papers reporting outcomes (either using RECIST 18 or number of patients shifting to ‘active treatment’) were included in this systematic literature review. Cross-referencing was carried out ensuring inclusion of all relevant articles. The flowchart depicting the study selection procedure is available in Supplemental Materials 2. Study selection Table 1. Inclusion and exclusion criteria of study selection procedure Inclusion criteria Exclusion criteria • Primary and recurrent DTF • Active surveillance (or other similar terms such as wait and see, expectative management etc.) as a primary treatment • Adult (aged ≥ 18 years) patients • English language • Reporting the outcomes of active surveillance in terms of reporting the success rate of active surveillance, numbers of patients needed to shift to active treatment, RECIST outcomes during active surveillance • Studies with patients receiving solely active forms of treatment such as surgery, systemic treatment, local therapy (e.g., cryotherapy), and radiotherapy • Case reports, case series ≤ 5 patients • Pre-clinical studies describing molecular features of DTF • Diagnostic studies describing imaging features of DTF • Non-original reports (e.g., editorials, study protocols, reviews etc.) • Non-full text available (e.g., conference abstracts etc.) • Studies describing solely paediatric cohorts • Studies describing solely FAP or Garner syndrome • Other subjects than DTF (e.g., soft tissue sarcoma) • Language other than English DTF, desmoid-type fibromatosis; RECIST, Response Evaluation Criteria in Solid Tumors; FAP, familial adenomatous polyposis 6