Systematic Review of Clinical Outcomes Following Various Treatment Options for Patients with Extraabdominal Desmoid Tumors

Background. Desmoid tumors (DT) are rare clonal proliferations that arise from mesenchymal cells. These tumors do not metastasize but are locally aggressive, and their growth may lead to significant morbidity. Their clinical course is both variable and unpredictable; tumors may rapidly progress but in other instances remain stable or regress without intervention. Aims. To examine current treatment of DT and assist with decision-making at time of presentation. Methods. A literature search was conducted of MEDLINE and Cochrane databases for published studies (1995–July 2015) using the search terms fibromatosis aggressive, desmoid with drug therapy, radiation therapy, prevention and control, radiotherapy, surgery, and therapy. Articles were categorized as surgery, radiation, surgery ? radiation, systemic therapy, and front-line observation. Articles were included if they reported a retrospective or prospective comparative or observational study with an analyzed sample size of 10 patients or more with confirmed diagnosis of desmoid tumor and described one of the following clinical outcomes: relapseor progression-free survival, local control rate, response rate. Results. 258 articles were reviewed; following screening for eligibility, 54 were identified; following full-text screen, 31 were included in final evaluation. The control rate for patients treated with a ‘‘wait and see’’ observational approach compared favorably with management with surgery and resulted in disease control rates of between 60 and 92%. Conclusions. Decision-making in this rare tumor is complicated by the range of treatment options available. Our evidence supports use of an upfront observational approach. Desmoid tumors (DT), also known as aggressive fibromatoses, are heterogenous benign lesions that originate from mesenchymal fibroblastic/myofibroblastic proliferation. They account for 0.03–0.1% of all solid tumors and 3.6% of fibrous tissue neoplasms. While tumorigenesis is linked to beta-catenin/Wnt/TcF signaling, the etiology of DT is unknown. Mutations within the B-catenin gene are harbored in 85–90% of DT, leading to nuclear accumulation of B-catenin. Clinically, DT may cause local symptoms due to pain, compression or inhibition of limb function. They can occur in any location in the body: predominantly limb girdles and proximal extremities, neck, trunk, abdominal wall, and within the bowel wall and mesentery. Intraabdominal tumors are frequently associated with Gardener’s syndrome. Due to their vastly different behavior and prognosis, intraabdominal tumors are not covered in this review. DT may behave aggressively, with deeply infiltrative growth patterns and high propensity for local recurrence. However, the natural history is unpredictable, varying from rapid, massive growth to long-term stability and spontaneous tumor regression, which has been reported in approximately 5% of cases. In 2013, Crago 12 released a nomogram allowing prediction of recurrence in DT. That multivariate analysis showed that extremity location, young age, and large tumor size, but not surgical margin, were associated with recurrence. Society of Surgical Oncology 2018 First Received: 5 November 2017 K. Smith, MBBS, FRACP e-mail: kortnye.smith@petermac.org Ann Surg Oncol https://doi.org/10.1245/s10434-018-6408-7