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risk factors are associated with survival, a systematic review was performed, which is described in Chapter II. After screening 2989 abstracts, 142 full-text papers were evaluated for eligibility. In total 22 studies were included, describing a total of 43 different prognostic factors, of which 17 were relevant to pre-treatment survival estimation. The prognostic factors most frequently associated with survival were the primary tumor and the performance status. The prognostic factors most frequently not associated with survival were age, gender, number and location of the SBM and the presence of a pathologic fracture. The evidence was inconclusive for the presence of visceral metastases and the presence of neurologic deficit. Therefore, prognosis of survival for patients with SBM should be based on an accurate primary tumor classification, combined with a performance score. The benefit of adding other prognostic factors was considered doubtful.
Stability
Next to life expectancy, spinal stability is one of the key factors to examine when deciding on treatment. Whereas patients with stable spines can be treated using non-invasive procedures such as radiotherapy, patients with unstable spines potentially require surgical fixation, either through minimally invasive techniques such as percutaneous stabilization or through more invasive procedures involving open fixation.
Assessment of spinal stability is challenging and in the absence of validated guidelines or an established predetermined set of risk factors, is mostly done by relying on clinical experience and radiological imaging. The absence of a standardized approach hinders communication between physicians of different medical specialties and can result in under- as well as overdiagnosis of spinal instability.
In 2010, the Spinal Oncology Study Group introduced the Spinal Instability Neoplastic Score (SINS); the first consensus-based guideline that aids in the assessment of a patient’s risk of spinal instability in the setting of neoplastic spinal disease.17 The SINS determines tumor-related instability based on six criteria and classifies the spinal column as stable, potentially unstable or unstable. Surgical consultation is recommended for patients with a spinal column classified as either potentially unstable or unstable. As such, the SINS facilitates interdisciplinary communication, assesses and categorizes spinal instability and assists in treatment
GENERAL DISCUSSION
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