[Desmoid tumors in patients with familial adenomatous polyposis (FAP). Clinical and therapeutic observations from the Heidelberg polyposis register].

The life-threatening event of early colorectal cancer in FAP patients may effectively be prevented by prophylactic colectomy. Desmoid tumors and periampullary carcinoma are now becoming the most frequent causes of death in FAP patients. Since the establishment of the Heidelberg polyposis registry in January 1991 we evaluated the frequency of desmoid tumors in 171 prospectively reexamined FAP patients. 29 patients (17%) with desmoid tumors were identified. In our series R0-resection with a wide security margin was performed in 12 cases, 3 of which developed a desmoid recurrence, 8 are free of desmoids and one treated for an intraabdominal desmoid states being well but refuses a radiological reevaluation. Tumor debulking was performed in 6 patients and led to an aggressive desmoid progression in 4 patients despite additional postoperative administration of tamoxifen and sulindac. Nonsurgical treatment with tamoxifen and sulindac seemed beneficial in 5 of 7 patients, 4 showed a stagnation of tumor growth, a reduction of an abdominal wall desmoid was documented in one female with a further intraabdominal desmoid. In life-threatening cases chemotherapy and radiation therapy may be considered. In two females radiation therapy resulted in a remarkable tumor reduction. The operative trauma of previous colectomy is considered the most relevant predisposing external factor inducing desmoid growth in FAP patients. 50% (11/22) of the desmoid tumors in our series were diagnosed within the first two years postoperatively, and 72% (18/22) of the desmoids developed within the first four years after colectomy.(ABSTRACT TRUNCATED AT 250 WORDS)