Extra-abdominal primary fibromatosis: Aggressive management could be avoided in a subgroup of patients

Objective: To evaluate the impact of surgery as first-line treatment on event-free survival (EFS) of primary aggressive fibromatosis. Patients and methods: Treatments were categorized into: surgery with or without radiotherapy and nonsurgical strategies with systemic treatment alone or wait and see policy. Eighty-nine patients had initial resection of their primary tumour followed by postoperative radiotherapy in 13 cases. Twenty-three did not undergo surgery but received systemic treatment or watch and wait policy. Results: Median follow-up was 76 months. Overall 3 years EFS was 49%. In the univariate analysis, patients with microscopically complete surgery had a similar outcome to patients in the no-surgery group (3 years EFS of 65% and 68%, respectively). Gender, age, tumour size, treatment period and strategy (surgery versus no-surgery) were not statistically significant. Quality of resection according to margins and the tumour site were the only prognostic factors. There was a significant correlation between tumour site and quality of surgery (p = 0.0002). Conclusions: A subset of patients with extra-abdominal fibromatosis could be managed with a nonaggressive policy, as growth arrest concerned 2/3 of nonoperated patients. When surgery is finally necessary, it should be performed with the aim of achieving negative margins.