Milea Timbergen

207 Supplementary Table 3. Inclusion and exclusion criteria of the literature search, applied at study level Inclusion criteria Exclusion criteria • Human subjects • Studies only reporting data on patients with a histologically proven primary DTF • Studies with at least one participant with age ≥ 18 years. • Studies with at least one participant having extra- abdominal or abdominal-wall DTF • Studies with at least one participant who received only surgical treatment for their DTF • Studies with at least one participant from which the CTNNB1 (β-catenin) mutation type is known. • Studies that report recurrence, recurrence rate, follow-up time, recurrence free survival, event- free survival, disease free-survival, report of a local recurrence rate, progression free survival, local recurrence rate, overall recurrence rate, and overall survival time. • Non-human models • Studies reporting about familial adenomatous polyposis exclusively • Studies reporting about intra-abdominal (mesentery) fibromatosis exclusively • Studies reporting about surgery in combination with other treatments exclusively • Studies describing a pediatric cohort (solely patients of 18 years and younger) DTF, desmoid-type fibromatosis Supplementary Table 4. Risk of bias assessed using the Quality In Prognostic Studies (QUIPS) tool 28 Study partici- pation Study Attrition Prognostic Factor Measure- ment Outcome Measure- ment Study con- founding Statistical analysis & reporting Overall risk of bias Kim et al. 43 Moderate Moderate Moderate Low Low Low Low risk Salas et al. 49 High High Low Low High Low High risk Nishida et al. 42 High Moderate Moderate Low Low Low High risk Mullen et al. 20 Low Low Low Low Low Low Low risk Mussi et al. 41 Low Moderate Moderate Low High Low High risk Van Broek- hoven et al. 22 Low Moderate High Low Low Low High risk Colombo et al. 23 Low Moderate Moderate Low Moderate Low Low risk When all domains were rated as low or moderate risk, a study was considered to be of low risk of bias When at least 1 domain was rated as high risk, a study was considered to be of high risk of bias 7