Effect of surgical margins on prognosis in aggressive fibromatosis: A single-institutional analysis of 90 patients.

The treatment of aggressive fibromatosis poses a therapeutic challenge in an interdisciplinary setting. The extent of surgical resection is still discussed controversially. The present retrospective analysis aimed to determine prognostic factors leading to recurrence. Between 2000 and 2014, 114 patients with aggressive fibromatosis were treated surgically at BG-University Hospital Bergmannsheil (Bochum, Germany). Univariate and multivariate analyses were restricted to 90 participants with information available on surgical margins at the initial procedure. The median follow-up time was 7.7 years. A total of 45 patients (50%) developed recurrence during follow-up. Primary tumors were resected with negative margins (R0) in 50 patients (68%) and with microscopically positive margins (R1) in 28 patients (25%). In addition, tumors in 12 patients (7%) were resected with macroscopically positive margins at the initial surgical procedure. The rates of recurrence-free survival (RFS) after 5 years were 68.8% [95% confidence interval (CI), 53.5-79.9%] in patients with R0-resected primary tumors and 34.1% (95% CI, 19.9-48.9%) in patients with R1/R2-status (P=0.001). Narrow and wide clear margins within the R0-group were not associated with significantly different outcomes. Adjuvant radiation, tumor site and patient age were not associated with a significant alteration of RFS. The current results suggest that the attainment of microscopically negative surgical margins at the initial surgical treatment is associated with a significantly improved prognosis. A conservative surgical approach involving the attainment of narrow negative margins while preserving function should be sought in patients in whom tumor resection is indicated. The decision for resection should be made interdisciplinary in each case based on tumor progression, available treatment alternatives and the decision of the informed patient.