Management of Low-Grade Myxoid Fibrosarcoma

Introduction to Treatment

The British Journal of Cancer recommends wide surgical excision with tumor-free margins performed by a sarcoma-trained surgeon as the definitive treatment for low-grade myxoid fibrosarcoma, followed by adjuvant radiotherapy for large, deep-seated tumors in elderly patients 1, 2

Mandatory staging for low-grade myxoid fibrosarcoma includes a chest CT scan to evaluate for pulmonary metastases, and an MRI of the primary tumor site to assess depth and resectability, as recommended by the Annals of Oncology 3, 4
The European Society for Medical Oncology suggests that abdominal imaging should be considered for myxoid tumors due to their propensity for unusual metastatic patterns 3, 4
A multidisciplinary tumor board review is mandatory before any intervention, involving pathologists, radiologists, surgeons, radiation oncologists, and medical oncologists at a sarcoma reference center, according to the Annals of Oncology 3, 4

The National Comprehensive Cancer Network recommends primary surgical resection to achieve en bloc excision with tumor-free margins (R0 resection) and at least 1-2 cm margins where anatomically feasible 1, 2
Minimal margins are acceptable only when adjacent to resistant anatomic barriers, as stated by the British Journal of Cancer and the Annals of Oncology 1, 3, 4

The American Society for Radiation Oncology strongly indicates radiotherapy for low-grade, deep tumors >5 cm, with a standard postoperative dose of 50-60 Gy in 1.8-2 Gy fractions, and a possible boost to 66 Gy if margins are close or positive 3, 4, 5
The European Society for Radiotherapy and Oncology suggests an alternative hypofractionated regimen of 50 Gy in 20 fractions (2.5 Gy per fraction) 5

The European Society for Medical Oncology states that chemotherapy is not recommended for low-grade fibromyxoid sarcomas due to their chemotherapy-insensitive nature, and adjuvant chemotherapy lacks proven efficacy even in high-grade sarcomas 3, 4

The International Society of Geriatric Oncology recommends considering age-related factors, such as functional status and comorbidities, which may limit tolerance of extensive surgery, and planned close margins supplemented with radiotherapy as an acceptable alternative if complete resection with acceptable morbidity is not achievable 1

The National Comprehensive Cancer Network recommends intensive surveillance, including history and physical examination every 3 months, and MRI of the resection site twice yearly for the first 2-3 years, then annually 2