Page 120 - Predicting survival in patients with spinal bone metastasesL

CHAPTER IX
Metastases to the spinal column in patients with end-stage malignant disease are a frequently observed complication of. Depending on their extent and localization, they cause a variety of clinical symptoms ranging from pain to neurological deficits and even paraplegia. Due to improvements in systemic treatment options for the primary tumor, overall survival times in patients suffering from metastatic disease are on the rise.1,2 Most likely, this will result in a prolonged palliative phase in which the incidence of patients presenting with symptomatic spinal bone metastases (SBM) will increase. Treatment with radiotherapy and/or surgery can be beneficial to patients presenting with pain, neurological deficit or both.3-5 However, the most optimal treatment algorithm for individual patients has not yet been established. In practice, the treating physician will match extent and type of treatment not only to a patient’s clinical presentation, but also to the expected survival time, thus balancing the increase in morbidity and mortality associated with more extensive treatment to the expected gain in quality of life.
Survival
Prediction of survival has become an integral part of selecting the appropriate treatment for patients suffering from SBM. Depending on the symptoms, patients with a short expected survival are most likely to benefit from short radiotherapy regimens, best supportive care or minimally invasive surgery. Patients with a relatively long expected survival could potentially benefit from high dose radiotherapy or – in the case of radioresistant tumors and (impending) biomechanical instability – more extensive surgical interventions. Several studies have shown that the estimation of survival by clinicians in terminally ill patients is inaccurate6 and have suggested the use of prognostic models in order to prevent exposure of patients to unnecessarily extensive treatments. Models that can be used in the decision making process have been developed by Tokuhashi, Bauer, Tomita, Van der Linden, Rades and several others.7-11 These models include prognostic factors such as primary tumor type, amount and location of spinal metastases, presence of visceral, brain and extraspinal bone metastases, functional status and neurological status.
However, clinical applicability seems limited due to over- or undertreatment and especially when predicting short survival the existing models fall short. Therefore, after an assessment of risk factors in a surgical cohort of patients described in Chapter III, we decided to create a new model. In the study described in
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