Factors predicting survival following complete surgical remission of pulmonary metastasis in osteosarcoma

Pulmonary metastasectomy (PM) is associated with improved survival of patients with metastatic osteosarcoma; however, the factors affecting survival following achievement of complete surgical remission remain controversial. The main objective of this study was to report the outcomes and prognostic factors of osteosarcoma patients who achieved complete remission (CR) following PM. We analyzed the effect of demographic and disease-related characteristics on the overall survival (OS) of consecutive patients with metastatic osteosarcoma who were treated at a single institution and achieved CR following PM, through univariate and multivariate analyses. Between January, 2000 and August, 2013, 62 patients with metastatic osteosarcoma were treated and followed up at our institution. A total of 25 patients achieved CR following PM and were included in this analysis. The 5-year OS and disease-free survival following PM were 30 and 21%, respectively. The factors correlated with inferior OS in the univariate analysis included chondroblastic subtype, post-chemotherapy necrosis <90% in the primary tumor, metastasis detected during neoadjuvant or adjuvant chemotherapy and pathological identification of tumor cells reaching the visceral pleural surface of any of the resected nodules. In the multivariate analysis, the chondroblastic subtype was the sole independent adverse prognostic factor (HR=4.6, 95% CI: 1.0-21.3, P=0.044). Therefore, factors associated with tumor biology, including poor tumor necrosis in the primary tumor and detection of metastasis during primary chemotherapy, are associated with poor post-metastasectomy survival. In addition, chondroblastic subtype and visceral pleural involvement predicted poor prognosis in our series.