(P 143) IMPACT OF SURGICAL MARGINS IN CHEST WALL CHONDROSARCOMAS: A CANSARCC STUDY

Objective: Chest wall chondrosarcomas necessitate en bloc resection to achieve local control due to their inherent resistance to adjuvant therapies. The thoracic surgery literature commonly recommends a 5 cm surgical margin for these tumors, which exceeds the margins typically employed for chondrosarcomas of the extremities or pelvis. The association between margin width, local recurrence, and overall survival in chest wall chondrosarcoma remains poorly defined. We assessed the influence of surgical margin status on local recurrence and survival outcomes in patients undergoing resection of chest wall chondrosarcomas.

Methods: Patients undergoing surgical resection of chest wall chondrosarcomas between 2000-2024 from 9 institutions were reviewed. Demographic, tumor characteristics, surgical details, post-resection overall (OS) and disease-free survival (DFS) data were retrospectively collected from the CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration) database. Overall and DFS were estimated using Kaplan-Meier curves and multivariable cox regressions were performed to evaluate predictors of survival and recurrence.

Results: 147 patients were included with 59 (40%) patients with low grade tumors and 82 (56%) had intermediate-high grade tumors. Negative margin surgery was achieved in 80% of cases, 12% had microscopic positive (R1) margins, and 2% had grossly (R2) positive margins. OS and DFS were 90% (± 3.2%) and 81% (±4.1%) at 2 years and 77% (± 4.8%) and 68% (±5.2%) at 5 years, respectively. Higher tumor grade and older age were independent predictors of worse overall survival while surgical margins did not impact survival. Higher grade tumors were predictive of local recurrence whereas overall margin and bony margin width did not predict local recurrence rates.

Conclusion: Contrary to conventional surgical principles advocating wider resections in the chest wall, wider margins did not independently influence overall survival or local recurrence rates. These findings suggest that aggressive attempts to achieve wider margins may not confer additional benefit and should be carefully weighed against the morbidity of more extensive resections in this anatomically complex region.

Patient Characteristics