Spinal Metastases & Metastatic Spinal Cord Compression (MSCC)

A metastasis is a deposit of cancer that has travelled from a primary, or original, tumour and established itself in a new site. When such deposits settle in the bones of the spine, they are called spinal metastases. They are not a cancer that begins in the spine; rather they are a feature of a cancer that began somewhere else and has spread.

The spine is the commonest site in the entire skeleton for cancer to spread to. Across the published literature, the spine is described as the site of around seventy per cent of bony metastases. The vertebrae are rich in red marrow, the active blood-forming tissue through which tumour cells circulating in the bloodstream tend to lodge and grow. The pattern of veins draining the spine, sometimes called Batson's plexus, offers a route by which tumour cells can reach the vertebrae directly. And the vertebral bodies carry the load of the upright skeleton, so a deposit that weakens the bone there has mechanical consequences.

The thoracic, or mid-back, region is involved most often, followed by the lumbar region of the lower back, with the cervical spine of the neck the least commonly affected.

Breast, prostate and lung cancers together account for the large majority of bony metastases, a figure often quoted at around eighty per cent. Kidney cancer, particularly renal cell carcinoma, and thyroid cancer are also well-recognised sources, both noted for sometimes producing deposits that are highly vascular. Multiple myeloma, a cancer of the plasma cells of the bone marrow, is mentioned alongside the metastatic carcinomas because it characteristically involves the spine. Other cancers, including lymphoma, melanoma and cancers of the gastrointestinal tract, are encountered too.

Lytic, or osteolytic, deposits are those in which bone is dissolved and removed faster than it is replaced, leaving an area of weakened, moth-eaten bone. Lung, kidney, thyroid cancers and myeloma characteristically produce lytic disease. Blastic, or osteoblastic, deposits are those in which excessive, disorganised new bone is laid down, producing an area of dense bone on imaging; prostate cancer is the classic source. Mixed deposits show both processes together, and breast cancer in particular produces a relatively even mixture.

Many spinal deposits are first seen on imaging performed for another reason, typically the CT, bone scan or PET-CT scans used to stage a known cancer or monitor its response to treatment. The other route is that a deposit makes itself felt — the commonest symptom is pain, classically pain felt at the level of the deposit, which may differ from ordinary mechanical back pain in being persistent, present at night, or unrelieved by rest. Importantly, a spinal metastasis is sometimes the very first sign that a person has cancer at all.

MSCC occurs when a deposit, or a vertebra that has collapsed around a deposit, presses on the spinal cord itself or, lower down, on the bundle of nerve roots known as the cauda equina. The pressure interferes with the function of the cord or roots, and if it is not relieved the resulting loss of function can become permanent. MSCC is recognised across cancer and spinal services as an oncological emergency, and dedicated pathways exist to identify and act on it without delay. The reason for this urgency is that the degree of neurological function at the time treatment begins is one of the strongest predictors of the eventual outcome.

The symptoms that specialist pathways associate with possible MSCC include escalating spinal pain, pain worse at night or when lying down, band-like pain around the trunk, pain provoked by coughing or straining, new weakness or heaviness of the legs, altered sensation, unsteadiness of gait, and disturbance of bladder or bowel control. The more obvious neurological signs often develop late, which is why earlier features such as a change in the character of spinal pain are given weight.

Magnetic resonance imaging of the whole spine is the central investigation in suspected MSCC and in the assessment of spinal metastases more broadly. Deposits are frequently present at more than one level, some causing symptoms and others silent; whole-spine MRI captures the full picture. MRI shows soft tissue and the spinal cord directly, demonstrating the precise level and degree of any compression. Specialist guidance describes the standard study as performed within defined timeframes that are shorter when neurological features suggesting cord compression are present. CT, bone scans and PET-CT complement MRI by showing bony detail and the wider skeletal picture.

The Spinal Instability Neoplastic Score (SINS), developed by the Spine Oncology Study Group, combines six factors — location, mechanical pain, lytic versus blastic nature, alignment, degree of vertebral collapse, and involvement of the back of the vertebra — to sort vertebrae into stable, potentially unstable and unstable categories.

The Bilsky, or epidural spinal cord compression scale, describes on MRI how far a deposit has encroached on the space around the spinal cord, from disease confined to bone through to frank compression with no fluid visible around the cord.

Decision frameworks such as NOMS bring these threads together: Neurological status, Oncological behaviour of the tumour, Mechanical stability of the spine, and the Systemic burden of disease and the person's general fitness. Prognostic scores such as the Tokuhashi and Tomita systems were developed to estimate likely survival and have historically informed how extensive any surgery should be. All of these tools support the multidisciplinary decision rather than replacing it.

Systemic therapy addresses the cancer throughout the body and includes chemotherapy, hormonal therapy, targeted agents and immunotherapy, together with bone-targeted medicines. Radiotherapy is a mainstay for many spinal deposits, used to relieve pain and to control the local growth of tumour; stereotactic body radiotherapy delivers a high, precisely shaped dose in a small number of treatments and has become important for durable local control in selected situations.

Surgery may be used to relieve pressure on the spinal cord, to stabilise a spine that has become or is at risk of becoming mechanically unstable, or both. A widely described modern strategy is separation surgery, in which the cord is decompressed and the spine stabilised with the aim of creating a small margin around the cord, after which stereotactic radiotherapy delivers durable tumour control. A landmark randomised trial reported that, for selected people with cord compression, surgery followed by radiotherapy preserved the ability to walk better than radiotherapy alone.

Spinal metastases are managed within a specialist multidisciplinary structure. In the United Kingdom this is reflected in national guidance and in the MSCC pathway, which brings together oncologists, radiologists, radiation oncologists, spinal surgeons, palliative care specialists and specialist nurses, often coordinated through a named MSCC coordinator who can mobilise rapid imaging and specialist opinion.

The outlook in spinal metastasis varies enormously, and it depends far more on the particular circumstances than on the diagnosis alone — the type of primary cancer, how it has responded to treatment, the extent of disease elsewhere, the person's general fitness, the mechanical state of the spine and, above all, the neurological situation at the time of treatment. Two themes recur: early recognition matters, particularly for cord compression, and outcomes have improved with better tools used through multidisciplinary care.

This page is general medical education and is not a substitute for individual advice. New or worsening weakness, numbness, saddle numbness, or any disturbance of bladder or bowel control requires urgent assessment.

• —NICE NG234 — Spinal metastases and metastatic spinal cord compression (2023)
• —NICE CG75 — Metastatic spinal cord compression in adults
• —NICE QS56 — Quality statement: Imaging for suspected MSCC
• —Tian F et al. Features of Spinal Metastases (PMC7931703)
• —Maccauro G et al. Physiopathology of Spine Metastasis (PMC3265280)
• —Fisher CG et al. The Spinal Instability Neoplastic Score (SINS). Spine 2010;35(22):E1221–E1229
• —Bilsky MH et al. Reliability analysis of the epidural spinal cord compression scale. J Neurosurg Spine 2010;13(3):324–328
• —Laufer I et al. The NOMS Framework. The Oncologist 2013;18(6):744–751
• —Patchell RA et al. Direct decompressive surgical resection for metastatic spinal cord compression: a randomised trial. Lancet 2005;366:643–648
• —Tomita K et al. Surgical strategy for spinal metastases. Spine 2001;26(3):298–306
• —Lockney DT et al. Stereotactic body radiation therapy for spinal metastases. Neuro-Oncology 2024;26(Suppl 1):S76

This information is for general patient education and is not a substitute for an individual consultation. Always seek personalised advice from a qualified spinal specialist.