Abstract 88P
Background
While active surveillance is recommended as first-line management for desmoid-type fibromatosis (DFs), we have limited data for rare locations, such as head and neck (H&N) and shoulders.
Methods
We specifically studied patients with DFs located in the H&N and shoulder, included in the ALTITUDES prospective cohort (NCT02867033). We compared their baseline characteristics using chi-square, Fisher exact, and Kruskal-Wallis tests, and outcome in terms of event-free survival (EFS), by estimating Hazard Ratios (HR), in Cox univariate model. A subgroup analysis was done in patients initially managed by active surveillance.
Results
H&N locations accounted for 4% of all DFs (27/610); shoulder locations accounted for 5% of all DFs (28/610). Their characteristics did not differ from other locations in terms of sex (p=0.17), age (p=0.43), history of polyposis (p=0.61), tumour size (p=0.49), multifocality (p=0.82), and presence of CTNNB1 mutation (p=0.45). Pain appeared significantly more frequent in H&N and shoulder locations compared to other sites (56% and 62% vs 33%, respectively; p=0.007); functional impairment was more frequent in shoulder compared to H&N and other sites (29% vs 0% and 6%, respectively; p=0.001). Overall, 63%, 86% and 66% of patients with H&N, shoulder and other site were initially managed by active surveillance (p=0.24). We observed no significant association between tumor site and EFS: 3-year EFS was 66%, 80% and 65%, in H&N, shoulder and other sites, respectively, with HR=0.92 (95%CI, 0.45-1.86) for H&N, and HR=0.74 (0.33-1.68) for shoulder location compared to the other locations (p=0.76). When focusing on patients initially managed by active surveillance, 3-year EFS was 51%, 78% and 61%, respectively, with HR=1.23 (0.57-2.63) and HR=0.73 (0.32-1.66) (p=0.64).
Conclusions
Pain and functional impairment significantly differed according to locations. Most patients with these rare locations were managed by active surveillance. Outcome of both H&N and shoulder DFs did not significantly differ from other locations.
Clinical trial identification
NCT02867033.
Editorial acknowledgement
Legal entity responsible for the study
Centre Oscar Lambret.
Funding
Ligue Nationale Contre le Cancer, Grant/AwardNumber: PRE2016.LCC/NP; SOS Desmoïde Grant; S.Wisnia; Intersarc; APICIL Fundation; Unicancer.
Disclosure
All authors have declared no conflicts of interest.