Pain is the most frequently reported symptom in patients with spinal tumors, affecting up to 80% [1]. Pain is multifactorial in patients suffering from spinal tumors. It can be subdivided into neurogenic, mechanical, and oncological pain.

Oncologic pain develops as the tumor invades the vertebral body and decreases its strength and integrity, thereby making the patient more susceptible to pathologic fractures. Expansion of the tumor in the vertebral body causes bone re-modeling and thinning of the cortex. A major source of oncologic pain is from the periosteum , as it is stretched from the expanding tumor burden. Eventually, the tumor causes pathologic fracture and invades into the paravertebral structures. Minor trauma could accelerate the process of pathologic fracture. The pain from pathologic fracture may be subtle initially, then gradually worsening to the point that it is persistent, even in a recumbent position. One of the most characteristic features of spine tumors is back pain that is persistent, even when the patient sleeps. The type of biologic pain associated with tumor oncology presents with pain in the evenings and mornings, which is usually responsive to steroids and radiation [2]. This type of biologic tumor pain is different from the pain of mechanical instability, which improves with the recumbent position.

According to the Spine Oncology Study Group (SOSG) , spinal instability is defined as the “loss of spinal integrity as a result of a neoplastic process that is associated with movement-related pain, symptomatic or progressive deformity, and/or neural compromise under physiologic loads” [3]. Pain from mechanical instability is an independent indication for surgical stabilization, regardless of the grade or radio-sensitivity of the tumor. Spinal instability is dependent on both radiographic and clinical criteria.

Clinically, mechanical pain differs from biologic tumor pain, in that it is exacerbated by activity and is problematic during the day. Mechanical instability in the subaxial spine is manifest by pain with flexion and extension [4]. Pain associated with thoracic instability is elicited with extension that causes unremitting pain as the patient straightens out an unstable kyphosis. Additionally, pain associated with mechanical instability in the lumbar spine is elicited with standing, which can cause severe radicular pain. Radiographically, instability can be assessed with dynamic imaging such as flexion/extension films.

Lastly, neurologic pain can occur from tumor compression of the spinal cord or nerve roots. Compression and invasion of the nerve roots by the tumor may result in nerve root irritation and radicular symptoms. This most commonly occurs with extramedullary-intradural tumors, such as schwannomas and neurofibromas. However, it can also occur with pathologic fractures from extra-dural tumor invasion of the vertebra with subsequent neural foraminal narrowing. In addition to causing neurogenic pain , tumor compression of neurologic structures may lead to motor weakness, loss of sensation, and bowel/bladder incontinence. For patients, who are presenting with neurologic deficits, it is important to evaluate the processes that resulted in the development of the deficit. Those who have been living with a deficit chronically from compression are less likely to regain any neurologic function. Conversely, neurologic decline must be treated promptly with decompression, as it halts further deterioration and may help to regain some of the lost neurologic function.

The primary goal of surgery with spine tumors is local control of the oncologic disease. As spine tumors include a wide variety of lesions from primary tumors of the bone to metastases of the spine, this discussion will focus on general concepts in the treatment of spinal oncologic processes. Surgery is the best treatment option for those patients with spinal instability, who are experiencing acute neurologic deficits or uncontrollable pain. Surgery is also indicated for patients with neurologic deficit before, during, or after radiotherapy. Goals of surgery are to decompress the spinal cord and nerve roots and to stabilize the spine. Gross total resection of the tumor is the primary oncologic goal of surgery. However, depending on the tumor, separation surgery may also be a reasonable option. This consists of creating a free plane between the tumor and the neural elements such that radiation may be administered to the tumor safely without risking radiation toxicity to the spinal cord [5].

Appropriate patient selection is critical when considering whether someone is a candidate for surgery. Factors that are considered include neurologic status, radio-senstitivity of the tumor, mechanical stability of the spine, and systemic tumor burden. Patients with heavy systemic tumor burden, in poor medical condition, and with short life-expectancy are not surgical candidates.