Should We Stop Assessing Intraoperative Frozen Section Marrow Margins During Ewing Sarcoma Resection?

Area of Science:

• Orthopedic Oncology
• Pediatric Oncology
• Surgical Pathology

Background:

• Ewing sarcoma, a rare pediatric bone cancer, presents diagnostic challenges for intraoperative margin assessment due to chemotherapy-induced bone marrow changes.
• Prior research has broadly questioned the utility of intraoperative frozen section margin analysis in bone sarcoma resections.
• The specific accuracy and clinical value of intraoperative bone marrow margin assessment in long bone Ewing sarcoma remain uncharacterized.

Purpose of the Study:

• To evaluate the accuracy of intraoperative frozen section assessment of bone marrow margins during long bone Ewing sarcoma resection.
• To determine the impact of positive intraoperative margin assessments on surgical plans.
• To assess the association between intraoperative margin assessment and oncologic outcomes, including local recurrence, metastasis, and survival.

Main Methods:

• Retrospective analysis of 64 patients undergoing primary resection of long bone Ewing sarcoma.
• Intraoperative frozen sections for bone marrow margins were assessed in 81% of patients.
• Comparison of frozen section results with final pathology, review of surgical changes, and Kaplan-Meier survival analysis for oncologic outcomes.

Main Results:

• All intraoperative frozen section assessments were 100% accurate when compared to final pathology; however, all positive frozen sections were false positives.
• Five of six patients with positive frozen sections underwent unnecessary additional bone resection.
• No significant differences in local recurrence-free survival, metastasis-free survival, or Ewing sarcoma-specific death-free survival were observed between patients with and without intraoperative margin assessment, or between true negative and false positive margin groups.

Conclusions:

• Routine intraoperative frozen section assessment of bone marrow margins in long bone Ewing sarcoma resection provides no clear clinical benefit and may result in excessive resection.
• Intraoperative frozen sections may be warranted only when a surgeon has specific concerns about positive margins.
• Given advancements in MRI, routine intraoperative frozen section margin assessment is likely unnecessary, potentially saving time and costs.