[Treatment of aggressive fibromatosis (desmoid). Reducing the rate of recurrence by postoperative irradiation].

Thirty-three patients with desmoid tumors were treated from 1 January 1970 through 31 December 1983 at the University Hospital in Basel. Twenty-nine patients were treated primarily by surgery in an attempt to cure. Sixty percent of these patients (17 of 29) suffered a subsequent recurrence. Of these 17 patients, 12 were treated with radiotherapy after a second operation. As a result, the recurrence rate was reduced to 25% (3 of 12). Following the initial tumor resection, 4 patients were treated by radiotherapy in an effort to cure. All 4 patients remain free of recurrence, with a median follow-up time of 56 months. The postoperative recurrence rate is dependent on age. No recurrences were observed in patients older than 40. In the younger patients, an increasing recurrence rate was observed the younger the patient. Radiotherapy can contribute to improved prognosis for desmoid tumors under the following circumstances: (1) when the tumor cannot be resected with histologically clear margins, or when resection margins are questionable; (2) when the patient is 30 years old or younger; (3) when the tumor is inoperable, or resectable only by means of a mutilating operation. For patients between 30 and 40 years of age, the question of postoperative radiotherapy should be discussed with the radiation oncologist, even following a microscopically complete resection.