Page 35 - Predicting survival in patients with spinal bone metastasesL

INTRODUCTION
Symptomatic spinal epidural metastases (SEM) continue to be a disabling consequence of cancer, causing a decrease in quality of life due to pain and neurological decline. With the development of better treatment options for the primary cancer, survival periods in metastatic disease will increase and will most likely lead to a rise in the incidence of metastatic spine disease. There is consensus on the fact that surgery can be beneficial to patients presenting with SEM,1-3 however, the optimal type of surgery to be used on an individual patient remains unclear. The goals of surgical intervention are to relieve pain and neurologic deficit by decompression of the spinal cord or cauda equina and stabilization of the spine. Surgical strategies to achieve these goals vary greatly in extent of tumor removal (ranging from debulking to en bloc resection of the affected vertebra) and type of stabilization (ranging from none to circumferential reconstruction with vertebral body replacement). Secondary to open surgery, minimal invasive techniques such as percutaneous vertebroplasty (PVP) or kyphoplasty and percutaneous pedicle screw fixation are increasingly used.
In practice the surgeon will match the type of surgery to the expected survival time, thus balancing the increase in morbidity associated with more extensive surgery to the expected gain in quality of life and mobility.
Models to aid in the selection of surgical candidates have been developed by Tokuhashi4,5, Tomita6, Van der Linden7 and Bauer8. Disadvantages of these models are that they vary in the amount and type of risk factors used (table 1) and the weight assigned to each of these factors, resulting in different scores for the same patient. Also, patient populations on which the models are based differ greatly; Van der Linden used data of radiotherapy patients only and Bauer based his model on a mixed group of patients with bone metastases to the extremities as well as the spine. As a consequence, the use of such a model entails a risk of over- or under treatment and clinical applicability is limited.
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SURGICAL COHORT
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