(P 517) PULMONARY METASTASECTOMY FOR SARCOMA: A SINGLE-INSTITUTION EXPERIENCE

Objective: Lungs are the most frequent site of metastatic disease for sarcoma patients. Pulmonary metastasectomy (PM) has become a common practice in the setting of sarcoma patients with pulmonary metastatic disease, with an impact on overall survival (OS). Given the heterogeneity, low incidence, and complexity of this group of diseases, its management should be carried out by experienced multidisciplinary teams.
The objective of this study is to review our experience with PM for sarcoma with metastatic involvement of the lungs.

Methods: We conducted a single-institution, observational retrospective study. All sarcoma patients with pulmonary disease who underwent curative intent PM at our center between 1995 and 2022 were included. Clinical and pathological data (age at PM, gender, tumor pathology, primary tumor site), as well as lung disease (distribution, number and size of pulmonary metastases) and treatment features (perioperative chemotherapy, surgical approach, and type of pulmonary resection) were collected from the electronic medical registry. Relapse of disease, repeated PM and outcomes were also registered, and disease-free-interval (DFI) and OS after PM were calculated.

Results: A total of 40 patients were included, 21 (52.5%) female. Mean age was 45.6 years (range 14–77). The most frequent histotypes were leiomiosarcoma (n=12, 30%), synovial sarcoma (n=11, 27.5%), pleomorphic sarcoma (n=4, 10%) and liposarcoma (n=3, 7.5%). Histological grade 3 was present in 21 cases (52.5%). The most frequent primary tumor sites were extremities (n=19, 47.5%), uterus (n= 9, 22.5%) and retroperitoneum (n=5, 12.5%).
Primary tumor surgery was performed in 38 (95%) patients, and the median interval between the treatment of primary tumor and PM was 21.5 months (range 2–189).
Metastatic pulmonary involvement was unilateral in 24 patients (60%) and bilateral in 16 (40%) patients. Multiple metastases were detected in 24 patients (60%), while 16 patients (40%) had just a single metastasis. Largest lung metastasis was bigger than 1 cm in 28 patients (68.7%).
Thoracotomy was performed as the chosen surgical approach for PM in 36 patients (90%) and thoracoscopy in 4 patients (10%). Wedge was the most frequent type of pulmonary resection (n=30, 75%). 10 patients (25%) received neoadyuvant chemotherapy, and 7 patients (17.5%) received adyuvant chemotherapy.
The median DFI after PM was 8 months (range 1–155), and pulmonary relapse was present in 31 patients (77.5). Repeated PM was performed in 15 patients (37.5%).
The median follow up was 68 months (range 8–345), and the median OS after PM was 44.5 months (range 2–302).

Conclusion: Our study found that PM is a reasonable therapeutic option for metastatic sarcomas with pulmonary disease, with acceptable DFI and OS.
More studies are needed to elucidate which patients are most likely to benefit from this strategy of treatment.