(P 375) DOES STAGED RESECTION WITH TEMPORIZING WOUND VACUUM INFLUENCE LOCAL RECURRENCE RISK? A MULTI-INSTITUTIONAL MATCHED COHORT ANALYSIS

Objective: For soft tissue sarcomas (STS), margin status is a significant predictor of local recurrence (LR). Staged resection with a temporizing vacuum-assisted closure (VAC) delays soft tissue coverage until final margins return negative, a strategy typically employed for locally aggressive histologies and highly infiltrative tumors. The objective of this analysis is to compare LR between patients treated with single-stage versus staged resection.

Methods: A matched cohort, multi-institutional retrospective review (2018-2024) was performed of STS patients undergoing localized resection. Patients treated with staged resection at two institutions (n=185) were matched by grade, depth, and radiation to patients treated with single-stage resection at a third institution (n=185). Demographics, tumor information, and treatment variables were collected. The primary outcome was LR.

Results: There was no significant difference in depth, grade, and radiation use between staged and single-stage groups. VAC patients were more likely to have had a prior unplanned surgery and a myxofibrosarcoma histology (p < 0.01) while tumor size tended to be smaller (6.4 vs 7.7cm, p=0.008). Initial margin status was more likely to be positive in the staged group (31 vs 18%, p=0.002), while final margin status was more likely to be negative in the staged group (94 vs 83%, p=0.001). However, the rate of LR was higher in the staged group (19.5% vs 5.5%, p< 0.001).

When controlling for potential confounders, initial positive margins increased LR risk (OR 4.5, CI 2.0-10.4), while radiation was protective (OR 0.3, CI 0.14-0.63). Final margin status, grade, and depth were not associated with LR.

Conclusion: Staged resection did not reduce LR. Initial margin status was a strong predictor of LR, indicating the first resection is the best opportunity for local control. Notably, higher LR rate in the staged group likely reflects a higher propensity for staging more locally aggressive tumors, such as myxofibrosarcoma. Further analysis is recommended to determine indications for staged resection for various histologies and tumor characteristics.