{Reference Type}: Observational Study
{Title}: Initial Active Surveillance Strategy for Patients with Peripheral Sporadic Primary Desmoid-Type Fibromatosis: A Multicentric Phase II Observational Trial.
{Author}: Bonvalot S;Cozic N;Le Cesne A;Blay JY;Penel N;Fau M;Chevreau C;Anract P;Waast D;Laurence V;Watson S;Duffaud F;Gouin F;Taieb S;Kind M;Lam L;
{Journal}: Ann Surg Oncol
{Volume}: 30
{Issue}: 13
{Year}: 2023 Dec 30
{Factor}: 4.339
{DOI}: 10.1245/s10434-023-14341-2
{Abstract}: <B>BACKGROUND: </B>Stabilization or spontaneous regressions are demonstrated in more than half of patients affected by primary desmoid-type fibromatosis (DF) in retrospective studies. The objective of this phase II study was to prospectively assess the behavior of primary sporadic DT managed by active surveillance (AS).<BR><B>METHODS: </B>This prospective, multicenter, observational study (NCT01801176) included patients ≥18 years of age with primary sporadic DF located in an extremity or the abdominal/thoracic wall. At inclusion, all patients were initially placed on AS. Follow-up was based on clinical and radiological evaluation by magnetic resonance imaging (MRI) performed at 1, 3, 6, 9, and 12 months, and then every 6 months for 3 years. The primary endpoint was progression-free survival (PFS) at 3 years according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, as evaluated by a Central Review Board.<BR><B>RESULTS: </B>Between 2012 and 2015, 100 patients were enrolled. The female/male ratio was 8 and the median age was 34 years (interquartile range [IQR] 30.8-43.9). Median follow-up was 46.6 months (IQR 36.8-61.1) and the 3-year PFS was 53.4% (95% confidence interval 43.5-63.1%). At progression (48 patients), 23 patients received active treatment. Fifty-eight patients (58%) presented with spontaneous tumor regression (decrease > 0% compared with the initial size) during the first 3 months (n = 35, 35%) or after an initial progression (n = 23, 23%), of whom 26 (26%) had partial responses (PRs). The median time to PR was 31.7 months (25.3-not available).<BR><B>CONCLUSIONS: </B>These data support the use of AS as the primary approach to select patients with peripheral DF who require aggressive treatment.