The Significance of a "Close" Margin in Extremity Sarcoma: A Systematic Review.

Background: An important measure of successful sarcoma treatment is the surgical tumor margin, yet defining and reporting the tumor margin has remained a source of controversy. Our study sought to determine whether there is a need to be more specific in classifying a margin by distinguishing a 'close' margin, or if simply calling a margin positive or negative is sufficient. Methods: We performed a comprehensive literature search in which all studies were reviewed independently by two separate reviewers. Studies eligible for inclusion and data analysis consisted of those that reported on at least ten patients with a primary sarcoma of the extremities who received limb-salvage or amputation surgery with a report of the final surgical margin as well as the histologic grade. Only studies that provided local recurrence outcomes with a minimum follow-up of two years were included. Results: Our literature search and article exclusion process resulted in 22 articles that contained 498 patients for data analyses. We found that the Enneking classification system distinguishes between intralesional, marginal, and wide/ radical margins, and that a close margin behaves closer to a positive margin than a negative margin. When all tumors were analyzed, a marginal margin gave a recurrence rate of 50.48% compared to an intralesional margin recurrence rate of 75.76% and a wide/ radical margin of 7.22%. A marginal margin set to a positive margin gave the highest sensitivity compared to comparing marginal margins to wide and intralesional margins alone. This was also observed when tumors were stratified into high-grade osteosarcomas treated with chemotherapy. In addition, we found that chemotherapy dramatically reduced local recurrence rates in osteosarcoma. Conclusions: Our literature search and data analysis showed that the Enneking classification system was able to give more information on local recurrence compared to a simple dichotomous system, and therefore may be considered a more successful predictor of treatment outcomes. As a result, this investigation may lead a suggestion of a practice-changing proposal of how surgical margins in sarcoma should be reported universally amongst multiple disciplines and institutions.