The significance of margins in pediatric Non‐Rhabdomyosarcoma soft tissue sarcomas: Consensus on surgical margin definition harmonization from the INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT)

Abstract

Background Margin status following surgery in children, adolescents, and young adults with soft tissue sarcomas is controversial and has been defined differently by various specialties, with definitions changing over time and by cooperative group. The International Soft Tissue Sarcoma Consortium (INSTRuCT) is a collaboration of the Children's Oncology Group (COG) Soft Tissue Sarcoma Committee, European pediatric Soft Tissue sarcoma Study Group (EpSSG), and the European Cooperative Weichteilsarkom Studiengruppe (CWS) devoted to improving patient outcomes by pooling and mining cooperative group clinical trial data. Methods The INSTRuCT non‐rhabdomyosarcoma soft tissue sarcoma (NRSTS) working group aimed to develop international harmonized recommendations regarding surgical margin assessment and definitions in children and adolescents with soft tissue tumors. Results and Conclusion This review addresses accepted principles and areas of controversy, including the perspectives of surgeons, pathologists, radiation oncologists, and pediatric oncologists, to develop a framework for building common guidelines for future research.

Local treatment in initially unresected non‐rhabdomyosarcoma soft‐tissue sarcomas of children and adolescents: A retrospective single‐center experience

“…For the definition of free margins, we adopted the criteria used in the EpSSG NRSTS 2005 study, i.e., ≥ 1 cm of healthy tissue around the tumor in all directions (when the tissue is a muscle), or > 1 mm of healthy tissue around the tumor when the tissue is periosteum, vessel sheath, epineurium, muscular fascia. 5,16 Radiotherapy was given in combination with surgery or as a unique local treatment. It was delivered as external beam irradiation, in most cases using megavoltage photon or electron beam energies, with con-ventional fractionation (1.8-2.0 Gy daily for 5 days a week).…”

“…Surgical reports were retrospectively reviewed for the purpose of this study. For the definition of free margins, we adopted the criteria used in the EpSSG NRSTS 2005 study, i.e., ≥ 1 cm of healthy tissue around the tumor in all directions (when the tissue is a muscle), or > 1 mm of healthy tissue around the tumor when the tissue is periosteum, vessel sheath, epineurium, muscular fascia 5,16 …”

Soft Tissue Sarcomas in Adolescents and Young Adults

“…Critical to the interpretation of data and design of impactful clinical trials in NRSTS is the establishment of consensus definitions on controversial issues such as margin status, grading, and staging. 63,90 International collaborations to facilitate clinical trial data harmonization are underway in pediatric NRSTS through INSTRuCT. 36,91 Similar efforts are needed among pediatric and adult international cooperative groups.…”

Emerging innovations and advancements in the treatment of extremity and truncal soft tissue sarcomas

“…A recent article published by Plastic and Reconstructive Surgery 37 discussed common complications after wide excision, including the importance of following techniques described by the reconstruction ladder 38 . While the children's oncology group INSTRuCT has started to define some consensus, 39 future questions still lie in delineating an optimal, morbidity‐minimizing strategy for reconstructive surgery techniques.…”