The Impact of Margin of Resection on Outcome in Pediatric Nonrhabdomyosarcoma Soft Tissue Sarcoma

Background/purpose: Because the management of pediatric nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) is determined by extrapolation from adult studies, the effect of margin of tumor resection and postoperative radiation therapy (RT) on local tumor recurrence in children has not been assessed.

Methods: Records of NRSTS patients from a single institution were reviewed with regard to demographic data, TNM staging, grade, histological type and site of primary tumor, RT, and local tumor recurrence. The margin of resection was determined by pathological review and did not necessarily reflect operative margins.

Results: Eighty-eight clinical group I patients were treated over a 30-year period. The most common histological tumor subtypes were synovial cell sarcoma (n = 26), malignant fibrous histiocytoma (n = 17), and fibrosarcoma (n = 7). The mean age was 9.4 years (range, 0 to 29 years). Thirty-four patients had high-grade tumors. Two of ten patients with low-grade tumors and margins less than 1 cm, including one of five who had received RT, had a local recurrence. Patients with low-grade tumors and margins greater than 1 cm (n = 44) had a lower recurrence rate (2 of 44, 4.5%). None of these patients had received RT. Fourteen patients with high-grade tumors had margins less than 1 cm. Seven of these had RT and had no recurrence. Three of the seven patients who received no RT had a recurrence (42.9%). None of the 20 patients with high-grade tumors and margins greater than 1 cm received RT; four of these patients had recurrences (20%). Seven of the 12 irradiated patients (58.3%) had serious radiation-associated complications (wound dehiscence, fracture, growth retardation, and joint dysfunction).

Conclusions: Grade alone does not determine the rate of local recurrence. In both low- and high-grade tumors, a pathological margin of resection greater than 1 cm reduced local recurrence. Radiotherapy provided no advantage in low grade tumors but did decrease local recurrence rates in high-grade tumors with less than 1 cm pathological margins.