Surgical outcomes of metastatic bone tumors in the extremities (Surgical outcomes of bone metastases)

Background: Skeletal related events due to metastatic bone tumors markedly affect the activities of daily living (ADL) and quality of life (QOL) in cancer patients. We focused on multidisciplinary therapy for metastatic bone tumors. This study aimed to evaluate the outcomes of surgical treatment for metastatic bone tumors in the extremities. Methods: We retrospectively reviewed 114 patients who underwent surgical treatment for metastatic bone tumors of the extremities between 2008 and 2019 and 69 patients were reassessed for more than 6 months after surgery. The most common primary tumor was renal, followed by lung, thyroid, and breast cancers. We assessed 69 patients’ performance status (PS), Barthel Index (BI) for ADL, EuroQol 5 Dimensions (EQ-5D) for QOL, and numerical rating scale (NRS) for pain and analyzed these postoperative values relative to preoperative values using Friedman’s test. The postoperative overall survival and the prognostic factors were evaluated using the Kaplan-Meier method, the log-rank test and Cox proportional hazards analysis. Results: The 1-year overall survival rate was 59%, and the median survival time after surgery was 20 months. Primary tumor, visceral metastasis, and surgical procedure were risk factors correlated with overall survival. PS, BI, EQ-5D, and NRS improved at 3 months after surgery and these improvements were maintained for 6 months after surgery regardless of the surgical procedure. Conclusions: The significant factors affecting survival after surgical treatment for bone metastases included the primary tumor, presence of visceral metastases, and internal fixation without tumor resection or curettage. Surgical treatment for metastatic bone tumors effectively reduced pain and improved PS, ADL, and QOL postoperatively after 3 months.