Surgical resection and radiation therapy of desmoid tumours of the extremities: results of a supra-regional tumour centre.

Purpose: Desmoid tumours of the extremity have a high recurrence rate. The purpose of this study was to analyse the outcome after resection of these tumours with special emphasis on recurrent disease and adjuvant therapeutic strategies.
Methods: In this retrospective study we evaluated prognostic factors for recurrence-free survival after surgical treatment of desmoid tumours of the extremity in 27 patients with an average age of 41 years treated from 1997 to 2009. Adjuvant radiotherapy (50-60 Gy) was given in five cases with primary and in nine patients with recurrent disease. The average follow-up was 64 months.
Results: The five-year recurrence-free survival in patients with primary disease was 33%. Patients with negative resection margins tended to have a better outcome than patients with positive resection margins, but the difference between both groups was not significant (56 vs 14%, p = 0.145). In patients with positive margins, adjuvant radiotherapy did not significantly improve recurrence-free survival (40 vs 14%, p = 0.523). Patients with local recurrence had a five-year further recurrence-free survival of 47%. In those patients further recurrence-free survival was significantly better after adjuvant radiation (89 vs 25%, p = 0.015). Two thirds of all patients suffered moderate or severe complications due to the treatment regimen.
Conclusions: Compared to desmoids of the trunk or the head and neck region, desmoids affecting the limbs show by far the worst outcome in terms of relapse or treatment-related morbidity. The importance of negative resection margins is still not clear. Particularly in recurrent desmoids adjuvant radiotherapy appears to reduce the further recurrence rate. Therefore, a general use of radiation should be considered for this high-risk group.