Clinical Characteristics and Treatment of Intra-abdominal Aggressive Fibromatosis: A Retrospective Study of 16 Patients

Desmoid tumors (aggressive fibromatoses) are benign neoplasms with high rates of recurrence after surgery. Radiotherapy is sometimes reported to prevent recurrences, but not in all studies. In order to evaluate the effect of radiation, comparative analysis was performed. The authors conducted a MEDLINE search and collected all articles in the English language on the treatment of "desmoid tumor" or "aggressive fibromatosis" from the years 1983-1998. They categorized treatment into three groups: surgery alone (S), surgery with radiotherapy (S + RT), or radiotherapy alone (RT). The S and S + RT groups were each subdivided according to whether margins were free (-), positive (+), or unknown. Each subgroup was divided into cases with primary, recurrent, or unknown tumor. The local control rates after treatment for cases in the S group with (-) margins, (+) margins, and overall were 72%, 41%, and 61%, respectively. For the S + RT group the local control results were 94%, 75%, and 75%, respectively, significantly different when compared with the results for the S group. For the RT group, the local control was 78%, significantly superior to that of the S group (61%). Cases with primary and recurrent tumors had significantly superior local control rates with S + RT or RT versus S. Radiotherapy complications noted were fibrosis, paresthesias, edema, and fracture. RT or S + RT results in significantly better local control than S. Even after dividing the groups into cases with free and positive margins and cases with primary and recurrent tumors, the best local control is achieved with RT or S + RT. Copyright 2000 American Cancer Society.

To construct a postoperative nomogram to estimate the risk of local recurrence for patients with desmoid tumors. The standard management of desmoid tumors is resection, but many recur locally. Other options include observation or novel chemotherapeutics, but little guidance exists on selecting treatment. Patients undergoing resection during 1982-2011 for primary or locally recurrent desmoids were identified from a single-institution prospective database. Cox regression analysis was used to assess risk factors and to create a recurrence nomogram, which was validated using an international, multi-institutional data set. Desmoids were treated surgically in 495 patients (median follow-up of 60 months). Of 439 patients undergoing complete gross resection, 100 (23%) had recurrence. Five-year local recurrence-free survival was 69%. Eight patients died of disease, all after R2 resection. Adjuvant radiation was not associated with improved local recurrence-free survival. In multivariate analysis, factors associated with recurrence were extremity location, young age, and large tumor size, but not margin. Abdominal wall tumors had the best outcome (5-year local recurrence-free survival rate of 91%). Age, site, and size were used to construct a nomogram with concordance index of 0.703 in internal validation and 0.659 in external validation. Integration of additional variables (R1 margin, sex, depth, and primary vs recurrent presentation) did not importantly improve concordance (internal concordance index of 0.707). A postoperative nomogram including only size, site, and age predicts local recurrence and can aid in counseling patients. Systemic therapies may be appropriate for young patients with large, extremity desmoids, but surgery alone is curative for most abdominal wall lesions.

Desmoid tumors describe a rare monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Although histologically benign, desmoids are locally invasive and associated with a high local recurrence rate, but lack metastatic potential. On the molecular level, desmoids are characterized by mutations in the β-catenin gene, CTNNB1, or the adenomatous polyposis coli gene, APC. Proof of a CTNNB1 mutation may be useful when the pathological differential diagnosis is difficult and location might be predictive for disease recurrence. Many issues regarding the optimal treatment of patients with desmoids remain controversial; however, surgery is the therapeutic mainstay, except if mutilating and associated with considerable function loss. Postoperative radiotherapy reduces the local recurrence rate, in cases of involved surgical margins. Because of the heterogeneity of the biological behavior of desmoids, including long periods of stable disease or even spontaneous regression, treatment needs to be individualized to optimize local tumor control and preserve patients' quality of life. Therefore, the application of a multidisciplinary assessment with multimodality treatment forms the basis of care for these patients. Watchful waiting may be the most appropriate management in selected asymptomatic patients. Patients with desmoids located at the mesentery or in the head and neck region could present with life-threatening complications and often need more aggressive treatment. This review describes treatment options and management strategies for patients with desmoid tumors with a focus on advanced disease.