By Alan Crockard and David Choi
Spinal epidural metastases are a common endstage of systemic malignancy causing pain, deformity and in some cases, incontinence and paralysis. Life expectancy may not be shortened but the quality of life in their last months may deteriorate markedly. Findlay (J Neurol Neurosurg Psychiatry 1984; 47:761–68), in a retrospective review, showed that decompressive laminectomy actually made the situation worse by encouraging deformity.
The therapeutic pendulum swung away from spinal surgery for a generation and radiotherapy was considered as the gold standard. However, spinal surgical techniques (including minimally invasive and percutaneous procedures) and the current sophisticated focused beam radiation have revolutionised therapeutic options. Patchell RA et al (The Lancet 2005; 366:643–48) in their landmark randomised controlled trial showed that surgery plus radiotherapy was significantly superior to radiation alone, though numbers were small and the study extended over 10 years.
The Global Spinal Tumour Study Group (GSTSG), now an independently funded charity, was formed some years ago by like minded spinal surgeons in different countries who agreed to enter prospectively their results and follow-up indefinitely. The first report (Ibrahim et al. J Neurosurg Spine 2008; 8:271–78) of 223 patients in 2008 confirmed low mortality and morbidity for these patients, but without recognised measurement of the quality of life from the patients’ point of view or at what cost. These latter variables form the basis of many current evaluations of therapies, but not often for spinal metastatic disease.
There are many quality of life measures that can report the patients’ view of their treatment and that can also report the cost effectiveness and the impact on the health economics of the treatment. The GSTSG have opted for the EQ-5D (the reasons for which have been outlined in a consensus statement that has been submitted for publication), a widely validated instrument in other medical and surgical conditions. Also noted in GSTSG are the visual analogue score for pain, Karnofsky, Tomita and Tokuhashi scores. All radiology, imaging and pathology are noted; the extent of the surgery is graded by the Tomita Staging System (Tomita K et al. Spine 2001; 26:298–306).
Currently, there are 12 centres in nine countries who are entering a minimum of 10 cases per year and provide six monthly follow up for as long as possible. Over the last 18 months, in excess of 300 patients have been entered on the electronic password protected database; the goal is to recruit several thousand patients.
Preliminary data reveal a wide range of surgical procedures have been employed for similar pathology, with a low operative mortality (around 4.6%) but with 18% incidence of systemic complications (such as chest infections, venous thrombosis etc). Universally, there has been a marked reduction in pain and a high level of patient independence. EQ-5D analysis has revealed significant improvement in quality of life after surgery and that this is sustained over time. Detailed results will be published soon, demonstrating the beneficial effects of modern spinal surgery, as measured by the patients themselves.
Alan Crockard is emeritus professor and David Choi is consultant neurosurgeon at the National Hospital for Neurology and Neurosurgery, London, UK