Desmoid tumor: Prognostic factors and outcome after surgery, radiation therapy, or combined surgery and radiation therapy

Purpose: To evaluate the therapeutic value of resection and the potential benefits of and indications for adjuvant and definitive radiation therapy for desmoid tumors. Materials and Methods: We performed a retrospective review of 189 consecutive cases of desmoid tumor treated with surgical resection, resection and radiation therapy, or radiation therapy alone. Treatment was surgery alone in 122 cases, surgery and radiation therapy in 46, and radiation therapy alone in 21. Median follow-up was 9.4 years. Results: Overall, 5- and 10-year actuarial relapse rates were 30% and 33%, respectively. Uncorrected survival rates were 96%, 92%, and 87% at 5, 10, and 15 years, respectively. For the patients treated with surgery, the actuarial relapse rates were 34% and 38% at 5 and 10 years, respectively. Among 78 patients with negative margins, the 10-year recurrence rate was 27%, whereas 40 margin-positive patients had a 10-year relapse rate of 54% (P = .003). Tumors located in an extremity also had a poorer prognosis than did those in the trunk. For patients treated with radiation therapy for gross disease, the 10-year actuarial relapse rate was 24%. For patients treated with combined resection and radiation therapy, the 10-year actuarial relapse rate was 25%. The addition of radiation therapy offset the adverse impact of positive margins seen in the surgical group. Conclusion: Wide local excision with negative pathologic margins is the treatment of choice for most desmoid tumors. Function-sparing resection is appropriate because adjuvant radiation therapy can offset the adverse impact of positive margins. Unresectable disease should be treated with definitive radiation therapy.