The AO Spine EPOSO (Epidemiology, Process and Outcomes of Spine Oncology) study is now concluded, and the final results are being submitted for publication. Initiated in 2013 with the support from the Orthopaedic Research and Education Foundation (OREF), the study enrolled 442 patients from ten centers located in three countries (Hungary, Canada, and the United States of America). The study generated eight publications, six international awards, and nearly 40 presentations at various congresses.
Principal Investigator Charles Fisher tells us that the EPOSO study has multiple important contributions to both research and clinical practice. The first is the validation of the Spine Oncology Study Group Outcomes Questionnaire version 2 (SOSGOQ2.0), a spine oncology-specific patient-reported outcome measure. With this tool, the spine oncology community can assess treatment outcomes in patients with spinal tumors in a standardized manner.
With this tool, the spine oncology community can assess treatment outcomes in a standardized manner.
The adoption of this instrument by the community will allow treatment effects to be compared across different treatment modalities in the future. To encourage global application of this instrument, members of the AO Spine Knowledge Forum (KF) Tumor and the community are now validating the SOSGOQ2.0 in Hungarian, Dutch, German, and Italian.
Another major achievement of the study is that EPOSO has helped us understand the benefits of surgery versus radiation in patients with spinal tumors. In the EPOSO study, patients in the surgical group (with and without radiotherapy) were on average worse off at baseline than patients in the radiotherapy group in pain, functional parameters, and health-related quality of life.
After surgical treatments, patients improved significantly in all outcome parameters and ended with outcome scores similar to those in the radiotherapy group at the last follow-up. In contrast, patients treated with radiotherapy alone had better scores at baseline but improved only in the pain aspect without a translation into improved quality of life. Still, one cannot conclude that surgical treatment was better in this patient population. Arjun Sahgal, KF Tumor Co-Chair says, "Patients with intermediate SINS (Spine Instability Neoplastic Score) are a tough population to study. For the first time, we are able to compare prospectively the benefits of surgery versus radiation in this cohort."
After surgical treatments, patients improved significantly in all outcome parameters.
Per definition of spinal instability, higher degrees of spinal instability should be associated with higher pain scores and more functional impairment. Results from the EPOSO study demonstrated this association. A manuscript is now in preparation for submission. This association is important because it means that the SINS could be used as part of the decision-making process to guide the treatments in patients with spinal tumors.
"There is no doubt that selected patients will benefit more from surgery than others; our task is to better identify these patients," says Sahgal. Although the EPOSO study has ended, the AO Spine MTRON registry continues collecting data on the same patient population, i.e., patients with metastatic tumor of the spine who received nonoperative and/or operative treatment for the tumors. The results from MTRON should further improve our understanding of the disease and optimize patient management.
“There is no doubt that selected patients will benefit more from surgery than others; our task is to better identify these patients."
The EPOSO study has answered some questions in the management of patients with spinal tumors, it has also opened up new research frontiers. Fisher says, "Data from EPOSO will allow the development of SINS into version 2. It will likely be more compact and shed greater light on the optimal treatment of patients in the SINS potentially unstable category."
Fisher attributed the great success to the importance of the research question and emphasized the dedication of the KF Tumor, the diligence of the study centers, and the support from the AO ITC for project management and data control. Last but not least, he gave a special acknowledgement to Christian Knoll for his statistic expertise and Anne Versteeg for coordinating the entire project.
