Editorial: Spine metastasis

Abstract

In this issue of the Journal of Neurosurgery: Spine, Fang et al.2 report their experience with anterolateral mini-open corpectomy and the posterior en bloc approach for the surgical treatment of solitary metastases of the thoracolumbar spine. Forty-one patients with solitary metastases of the thoracolumbar spine underwent either of the 2 procedures, and outcomes were assessed by survival, neurological function, local recurrence, and pain in this retrospective clinical trial. Mean blood loss and operative times were significantly lower in the mini-open corpectomy cohort. No difference was detected in the visual analog scale scores for both groups, but the local recurrence rate of the total en bloc spondylectomy (TES) group was lower than that of the mini-open corpectomy group (p < 0.05). Postoperative survival at 2 years was similar for the 2 groups. Complication rates were higher in the mini-open approach, although the difference was not statistically significant. The authors concluded that the mini-open anterior corpectomy approach is an effective option in the treatment of solitary metastases of the thoracolumbar spine. This study aims to present a less invasive approach to treat spinal metastases, and the reported results are encouraging. However, this trial is certainly not conclusive or definitive, because it is inherently limited by its retrospective nature and small sample size. Furthermore, a direct comparison of the 2 techniques for the same primary tumor histology was not made, thus potentially confounding the true outcomes and comparison. For example, there were a greater number of patients with metastases from breast and thyroid cancer, which are known to have longer survival, in the mini-open compared with the TES group. The only potentially comparable group could have been those patients with lung cancer as the primary cancer, but stratified data were not available for this subset of patients. While operative duration and blood loss were more favorable in the mini-open group, there is no objective clinical benefit born from this difference. In fact, as the authors demonstrate, pain scores and overall survival were not statistically significant, confirming the lack of significance of these parameters in this comparison. Although the potential benefits of reduced operative time and blood loss may be associated with decreased incidence of wound infection and decreased costs, these variables were not measured in this study. The overall survival in this study was not different at 2 years between the TES and the mini-open group, but recent studies suggest increased survival with TES for a subset of patients with metastatic disease with solitary lesions.1,4 In patients with controllable primary cancer, solitary spinal metastasis, and no evidence of systemic metastases, TES may remain the best option for local disease control, and perhaps increased survival. The authors, however, are to be commended for reporting their experience with the mini-open approach for thoracolumbar metastatic tumors. Given the aging population, more patients are presenting with increased comorbidities and are considered highrisk surgical candidates. Less invasive approaches, if equally effective, should be pursued, particularly when the primary goal of surgery is palliation.3,5 (http://thejns.org/doi/abs/10.3171/2012.5.SPINE12337)