The treatment of choice is resection to achieve clear margins. If postoperative margins are positive, 70% of patients will have a recurrence of disease. Postoperative radiation therapy is a consideration when progression would entail additional surgery that might cause functional or cosmetic compromise and if radiation is considered acceptable in terms of morbidities. When the diagnosis is known and complete surgical excision is not feasible, and if the tumor poses significant potential for mortality or morbidity, preoperative strategies may include the following:[18,19]
- Antiestrogen therapy.
- Nonsteroidal anti-inflammatory agent therapy.
- Postoperative interstitial iridium-192.
- External-beam radiation therapy.
Evaluation of the benefit of interventions for treatment of desmoid tumors has been extremely difficult, because desmoid tumors have a highly variable natural history.
Large adult series and a single pediatric series have reported long periods of disease stabilization and even regression without systemic therapy.[14,20] Combination chemotherapy using vinblastine and methotrexate produced objective responses in about one-third of patients with recurrent or unresectable desmoid tumors. A small series of mainly adult patients (N = 19) with desmoid tumors were treated with imatinib mesylate and showed infrequent objective responses. A series of mainly adult patients with familial adenomatous polyposis and unresectable desmoid tumors that were unresponsive to hormone therapy showed that doxorubicin plus dacarbazine followed by meloxicam (a nonsteroidal anti-inflammatory agent) can be safely administered and can induce responses. Pegylated liposomal doxorubicin has also been used with some responses.
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as sulindac have been used in single cases for desmoid tumors; the responses seen were usually disease stabilization. Similar results have been seen with antiestrogen treatment, usually tamoxifen. In some trials, these drugs were used in combination.
Radiation has been used for unresectable desmoid tumors or adjuvantly for tumors with inadequate resections. The potential long-term complications of radiation therapy, especially subsequent neoplasms, makes use of this modality less appealing in a young population.
Partially excised or recurrent lesions that do not pose a significant danger to vital organs may be monitored closely if other treatment alternatives are not available.[14,26,27,28,29] Whenever possible, however, the treatment of choice is complete resection.
There are two distinct types of fibrosarcoma in children and adolescents: infantile fibrosarcoma (also called congenital fibrosarcoma) and fibrosarcoma that is indistinguishable from fibrosarcoma seen in adults. These are two distinct pathologic diagnoses.
Infantile fibrosarcoma usually occurs in children younger than 1 year. It occasionally occurs in children up to age 4 years. It usually presents with a rapidly growing mass, often noted at birth or even seen in prenatal ultrasound. The tumors are often quite large at the time of presentation. The tumor usually has a characteristic cytogenetic translocation t(12;15)(ETV-NTRK3). Infantile fibrosarcoma shares this translocation and a virtually identical histologic appearance with mesoblastic nephroma. These tumors have a low incidence of metastases at diagnosis.