Standard treatment remains the recommended approach for patients with bone sarcoma who underwent unplanned surgery: Report from the Japanese musculoskeletal oncology group

Background: The outcomes of unplanned surgery for bone sarcomas have not been frequently discussed. However, it is important to recognize patterns, treatment, and clinical outcomes of unplanned surgeries for patients with bone sarcomas. This multicenter study aimed to character-ize the clinical outcomes of patients with bone sarcomas who underwent unplanned surgeries. Patients and Methods: Data of 43 patients with bone sarcomas who underwent unplanned surgery between 2006 and 2017 were obtained from 23 hospitals in Japan. These included 18 cases of osteosarcoma, 9 of Ewing sarcoma, 8 of chondrosarcoma, and 6 of undifferentiated pleomorphic sarcoma. The study included 28 men and 15 women, with a mean age of 46 years. The mean follow-up duration was 59 months. Results: The main primary tumor sites were the femur (n = 19), spine (n = 6), pelvis (n = 5), tibia (n = 3), and humerus (n = 3). The primary diagnoses were benign bone tumor (n = 24), trauma (n = 7), bone metastasis (n = 5), osteomyelitis (n = 4), degeneration (n=2), and unknown (n = 1). As unplanned surgeries, curettage, with or without bone graft, was performed in 26 patients; internal fixation was performed in 7; spinal surgery in 5; arthro-plasty in 4; and arthroscopy in one. Thirty-eight patients received additional standard treatments. Thirty-four of these patients underwent surgical tumor resections, including amputation (n = 10), and the remaining 4 received radiotherapy or carbon ion radiotherapy as additional standard treatments. The 5-year disease-specific survival (DSS) rates in patients with osteosarcoma, Ewing sarcoma, and chondrosarcoma were 65.5%, 58.3%, and 72.9%, respectively. Twelve (27.9%) patients developed local recurrences (LR); among the total 43 patients studied, the 5-year DSS rates were significantly worse for those who developed LR compared to those who did not (p = 0.03). The 5-year DSS rates in patients with and without LR were 44% and 73.8%, respectively. Conclusion: We recommend that patients who have undergone unplanned surgery be administered standard treatment, including the option of amputation because herein, LR was shown to be a risk factor for decreased DSS.