(P 054) PROGNOSTIC FACTORS AFFECTING SURVIVAL OF PATIENTS WITH PRIMARY MUSCULOSKELETAL SARCOMAS FOLLOWING PULMONARY METASTASECTOMY

Objective: As of today, pulmonary metastasectomy (PM) is the therapeutic treatment of choice to offer a curative treatment for sarcoma patients with pulmonary metastases. Unfortunately, many patients are not suitable for PM due to metastasis extent and location, ability to obtain a complete metastatic resection, pleural cavity extension or patient general health status. Even though many prognosis factors for surgical success have been identified in the literature, no consensus have been reached and patient selection modality for this procedure is still controversial. The purpose of this study is to optimize selection criteria for candidates that could benefit from a surgical procedure for sarcoma pulmonary metastases.

Methods: We retrospectively collected and reviewed medical records of patients from the 3 recognized sarcoma centers of the province of Quebec diagnosed with pulmonary sarcoma metastases, who underwent a PM procedure between 01/01/2009 to-01/01/2019. The primary objective was to identify factors that may have an impact on the patients’ overall survival (OS). The secondary objective was to define factors that may have an impact on the patients’ event-free survival (EFS) after Metastasectomy PM and, by doing so, help select patient who would truly benefit from aggressive surgical removal of pulmonary metastases.

Results: Patients who develop asynchronous pulmonary metastasis had significant better OS (p=0.032) compared to synchronous pulmonary disease. The mean estimated OS for patients with synchronous metastasis was 33 months compared to 64 months for asynchronous. Significant better OS (p=0.022) was also found for unilateral vs bilateral metastasis. Recurrence of pulmonary metastasis occurred in 42 (75%) of patients, local recurrence or distant metastasis in 11 (15%) patients. A statistically significant correlation was also found between histology and EFS (p=0.003). All patients with positive margins developed an early pulmonary recurrence. Vascular involvement of resected metastasis had a significant impact on EFS.

Conclusion: The decision to perform a PM should be considered on a case-by-case basis in a multidisciplinary forum. We presented practical recommendations for patient selection for PM. Patients with asynchronous appearance, unilateral disease, less than 4 metastases, and metastasis diameter smaller than 20 mm should be considered for a PM. Repeated PM for later recurrences should be considered as they can still lead to long lasting survival.