Local Control and Survival Outcomes in Pediatric Nonrhabdomyosarcoma Soft Tissue Sarcoma: The Mayo Clinic Experience
Elizabeth L. McKone, Kristofer W. Roberts, William S. Harmsen, William G. Breen, Anita Mahajan, Wendy A. Allen-Rhoades, Peter S. Rose, Nadia N. Laack, Safia K. AhmedObjective:
This single institutional analysis explored outcomes and factors associated with local control and survival in pediatric patients with nonrhabdomyosarcoma soft tissue sarcoma (NRSTS).
Methods:
Patients 18 years of age or younger diagnosed between October 1990 and November 2021 who received external beam radiotherapy (EBRT) were retrospectively identified. Overall survival (OS) and disease-free survival (DFS) were analyzed using Kaplan-Meier methods and univariate Cox models.
Results:
Among 51 included patients, there were 33 extremity tumors (65%), with 80% T1/T2 and 90% M0. Surgery in 49/51 (96%) resulted in 32 (65%) R0 resections. All received EBRT, with brachytherapy or intraoperative radiotherapy boosts in 21/51 (41%). Thirty-four (66.7%) received chemotherapy. With 5.7 years median follow-up, 5-year OS and DFS were 70.7% and 67.9%, respectively. Positive margins were significantly associated with worse OS. Two-year local failure incidence was 18.1% for EBRT versus 5.3% for EBRT+boost (HR 3.67,
Conclusion:
Multimodality treatment of pediatric NRSTS results in 5-year OS and DFS around 70%. Although complete resection remains essential, and the modern incidence of R1 resection has declined, IORT/brachytherapy boost may continue to have a role in selected patients with a high local recurrence risk.