Diagnosis and treatment of spinal cord compression in malignant disease

Abstract

Compression of the spinal cord and cauda equina from metastatic disease is a major cause of morbidity in patients with malignant disease. Compression usually results from epidural tumour mostly extending from an adjacent vertebral metastasis, or more sporadically from bony impingement from a pathological vetebral fracture. Since there is essentially no difference in pathophysiology and outcome (1, 2, 3) between compression of the spinal cord and of the cauda equina we will use the term epidural spinal cord compression (ESCC) for epidural compression at any level of the spinal canal. Epidural spinal cord compression is, next to brain metastasis, the most common metastatic neurological complication. Epidural metastasis is found at autopsy in 5% of patients with cancer but diagnosed during lifetime in 1% or less (4, 5). Several reviews (6, 7, 8, 9, 10) emphasize the clinical importance of ESCC. The incidence of epidural metastasis will increase with improving therapies for patients with metastatic disease. Epidural spinal cord compression needs special attention because of its debilitating complications including severe pain, paraplegia and loss of sphincter control. Neurological deficit often evolves rapidly, and the response to treatment is usually poor once serious dysfunction has developed (11, 12, 13, 14, 15). The pretreatment neurological status is the most important prognostic factor affecting neurological outcome, more so than the nature of the primary tumour and the mode of treatment. The majority of the patients who are able to walk before treatment remain ambulatory, whereas only a minority of the non-ambulatory patients regain walking ability. In general, less than half of the patients are still ambulatory at the diagnosis ESCC (2, 12, 16, 17, 18), and this low proportion of ambulatory patients is only slightly improved by treatment (2, 12, 19, 20). Since ESCC is in itself not fatal, permanent and incapacitating deficit has important clinical and social implications. About 35% of the patients with ESCC are still alive 1 year after the diagnosis (2, 21, 103). Recognition of the importance of early diagnosis has resulted in several algorithms (22, 23, 24), proposed to aid the clinician in early detection of ESCC. With the advent of magnetic resonance imaging (MRI) early detection of epidural tumour will be further facilitated. At this moment, however, the proportion of nonambulatory patients at the diagnosis of ESCC in most series still does not differ