Surgery

Surgical resection of the primary tumor is the predominant therapy for most NRSTS. In the COG ARST0332 (NCT00346164) study, approximately 37% of patients younger than 30 years were treated with surgery alone.[1] Another 36% of patients had surgical resection after neoadjuvant chemoradiation therapy. Involvement of a surgeon with special expertise in the resection of soft tissue sarcomas is highly desirable.

After an appropriate biopsy and pathological diagnosis, every attempt is made to resect the primary tumor. Completeness of resection predicts outcome. In the COG ARST0332 study, complete resections with negative microscopic margins (R0) resulted in the best outcomes.[1]

The COG reported results for the subset of patients with low-grade NRSTS enrolled in the ARST0332 study.[2] Low-risk patients were treated with surgery alone. Intermediate- and high-risk patients received ifosfamide/doxorubicin and radiation therapy, with definitive resection either before or after 12 weeks of chemotherapy and radiation therapy.

The timing of surgery depends on an assessment of the feasibility and morbidity of surgery. In the COG ARST0332 study, if the central review surgeon deemed the tumor unresectable without loss of limb, form, or function, the patient was treated in arm C with neoadjuvant radiation therapy. Surgery was performed 4 to 6 weeks after the completion of radiation therapy. This early surgery allowed for decreased morbidity, better wound healing, and more complete surgical resection. The outcomes in the COG ARST0332 study were nearly identical for intermediate-risk patients who achieved an R0 or R1 resection with up-front surgery or surgery after neoadjuvant chemoradiation therapy (70% vs. 71%, respectively). An R0 resection was more likely to occur after neoadjuvant therapy.[1] These observations are true even for high-grade tumors, where the ability to achieve R0 or R1 resections was the major predictor of EFS. Treatment with neoadjuvant chemoradiation therapy resulted in lower doses of radiation therapy and achieved greater rates of R0 resections.[3] Resectability should be determined at the time of diagnosis. While there should be an emphasis on achieving negative margins without loss of form or function, given the variability of chemosensitivity of such diverse tumors, it may be better to tailor the resection to histology for each patient.

If the initial operation fails to achieve pathologically negative tissue margins or if the initial surgery was done without the knowledge that cancer was present, a re-excision of the affected area is performed to obtain clear, but not necessarily wide, margins.[4-7] This surgical tenet is true even if no mass is detected by magnetic resonance imaging after initial surgery.[8]; [9][Level of evidence C1]

Regional lymph node metastases at diagnosis are unusual and are most often seen in patients with epithelioid and clear cell sarcomas.[10,11] Sentinel lymph node biopsy as a staging procedure in soft tissue sarcoma remains controversial. However, it may help manage selected cases in adults with clear cell sarcoma and epithelioid sarcoma. There are insufficient data to support the use of sentinel lymph node biopsy in the management of pediatric patients with other NRSTS.[12-17]