Long-term outcomes and prognostic factors of pulmonary metastasectomy for osteosarcoma and soft tissue sarcoma Abstract Background The prognostic factors of pulmonary metastasectomy in patients with osteosarcoma and soft tissue sarcoma remain controversial. The purpose of our analysis was to explore the prognostic factors and outcomes of patients with osteosarcoma and soft tissue sarcoma who underwent pulmonary metastasectomy at our institution. Methods We reviewed the data of 44 patients who underwent resection of pulmonary metastases from 1996 to 2016 at our institution. The Kaplan–Meier method, log-rank test and multivariate Cox hazard model were used for comparison and survival analyses. Results There was no perioperative mortality. The median post-metastasectomy overall survival was 24.8 months, and the 5-year overall survival rate of all patients was 43.5%. The 5-year survival rate of the patients who underwent repeat thoracotomies was 60.0%. Incomplete resection, a largest tumor size > 2 cm and a disease-free interval < 12 months were associated with poor survival in multivariate analyses. Among eight patients, who underwent repeat pulmonary resection, two remain alive with no evidence of disease. These patients had the longest DFI and DFI-2 (time from first pulmonary metastasectomy to the diagnosis of recurrent pulmonary metastasis), respectively. Conclusion The survival of patients with a relatively long disease-free interval, small tumor size and complete resection was favorable following the treatment of osteosarcoma and soft tissue sarcoma with pulmonary metastasectomy. Repeat pulmonary metastasectomies also provide favorable prognosis in select patients.