Metastatic Epidural Disease

Metastatic epidural disease is cancer that has spread into the bones of the spine or into the space just outside the spinal cord. Epidural means outside the dura, and the dura is the tough sheath that wraps the cord. When that tissue grows, or when a spine bone collapses into it, the cord gets squeezed. Teams then call it metastatic spinal cord compression, usually shortened to MSCC.

NHS Scotland's palliative care guidelines put it simply. MSCC "occurs when the dural sac and its contents are compressed at the level of the cord or cauda equina." The cauda equina is the fan of nerve roots that hangs below the point where the cord itself ends, low in the back.

Epidural disease and cord compression are not the same thing. One can turn into the other. It is fair to ask your team which of the two your scan shows.

Go to an emergency department, or call 911 or your local emergency number, if any of these begin or get worse:

• New leg weakness, legs that give way, or new trouble walking.
• New numbness or pins and needles, especially in both legs.
• Numbness in the saddle area — the parts that would touch a bicycle seat: inner thighs, buttocks, genitals.
• Any change in bladder or bowel control. That includes leaking. It also includes being unable to pass urine at all.
• Back or neck pain that is worse lying flat, worse at night, or worse when you cough, sneeze or strain.

MedlinePlus is direct about back pain in someone with cancer. Contact your provider "if you have a history of cancer and develop severe back pain that is sudden or gets worse." And, for someone already being treated for a spinal tumour: "Go to the emergency room or call 911 or the local emergency number if you develop new symptoms, or your symptoms get worse during the treatment of a spinal tumor."

What you need is an MRI the same day. Not an appointment in two weeks. NHS Scotland states that "an urgent MRI should be performed, ideally within 24 hours." Macmillan is just as clear: "Spinal cord compression is an emergency that needs treatment as soon as possible." Call the cancer center even at night, on a weekend, or on a holiday. If nobody answers, go straight to the emergency department.

Here is why the clock matters this much. Function lost before treatment often does not come back. MedlinePlus says: "Treatment should be given quickly. The more quickly symptoms develop, the sooner treatment is needed to prevent permanent injury." A StatPearls review is blunter. "Severe weakness and inability to ambulate for more than 48 hours before diagnosis are both associated with poor neurologic outcomes." Ambulate means walk. Someone still walking when treatment starts usually keeps walking. Someone who has already stopped often does not get it back.

Bone is one of the places cancer cells settle. NCI lists bone as a common site of spread for bladder, breast, kidney, lung, melanoma, prostate, thyroid and uterine cancers. It notes that bone spread causes "pain and fractures."

The spine is bone with a nerve cable running through it. That is the whole problem.

StatPearls reports that MSCC develops in "2.5% to 5% of patients dying as a result of cancer." Its review of 75,876 hospital admissions found lung cancer (24.9%), prostate cancer (16.2%) and multiple myeloma (11.1%) leading the list. Macmillan names breast, lung and prostate cancers and myeloma as the more common sources.

Where it sits changes what you feel. StatPearls: "the thoracic spine is most commonly implicated in MSCC, followed by the lumbar and cervical vertebral levels." The thoracic spine is the mid back, behind the ribs. So mid-back pain in a person with cancer deserves more attention than most people give it.

Pain is the early sign, and it is easy to explain away. StatPearls reports back pain in "80 to 95% of patients." Motor problems — weakness, trouble walking — are present in only 35 to 75% at the time of diagnosis. So pain usually arrives before weakness does. That gap is your window.

The pain has a character. StatPearls describes it as "constant, aching, classically worse at night, and with Valsalva maneuver." Valsalva is what you do when you strain: coughing, sneezing, bearing down on the toilet. Macmillan adds back pain that is severe, is getting worse, "gets worse with movement," "gets worse with straining, for example – when coughing or emptying your bowels," and "disturbs your sleep." NHS Scotland is the source for the lying-down part: it lists "mechanical pain (aggravated by standing, sitting, lying or moving)" and "night-time back pain disturbing sleep."

That last one is the tell. Ordinary back strain tends to ease when you lie down. This kind often gets worse. If pain drives you out of bed at three in the morning, say exactly that out loud.

Contrast MRI is the test. The contrast is gadolinium, a dye given through a vein that makes abnormal tissue stand out. StatPearls calls contrast-enhanced MRI "the gold standard for diagnosing MSCC (sensitivity 93%, specificity 97%)" and adds that "imaging of the entire spine is advised."

The entire spine, not one level. Disease is often in more than one place, and a scan aimed only where it hurts can miss a second spot that has not started hurting yet. If your team images one region, ask whether the rest of the spine was covered. Macmillan notes that a CT scan may be used if MRI is not available.

Steroids. Dexamethasone is usually started at once to bring down swelling around the cord. StatPearls describes a standard hospital protocol of a first dose into a vein followed by regular smaller doses through the day, and notes that pushing the amount higher caused more side effects without better neurological results. NHS Scotland splits its daily amount into a morning and a lunchtime dose, given no later than early afternoon, because late doses keep people awake. Whichever protocol your hospital follows, the amounts are set and given by the ward team. NHS Scotland also advises "gastroprotection with proton pump inhibitor (PPI) or famotidine," because steroids irritate the stomach lining. Expect blood sugar checks as well. Do not stop dexamethasone suddenly on your own.

Position. Until the spine is known to be stable, movement is limited. NHS Scotland describes "nursing in bed, as pain allows, with log rolling initially." Log rolling means being turned as one piece, shoulders and hips moving together, so the spine does not twist.

Radiotherapy. Macmillan says "the most common treatment is radiotherapy," with surgery or drug treatments offered to some people depending on the type of cancer. Ask how many sessions are planned. Radiotherapy can ease pain as well as pressure.

Surgery. Surgery takes pressure off the cord and steadies a spine that is breaking down. MedlinePlus notes that "emergency surgery may be needed to relieve compression on the spinal cord," and that radiation "may be used with, or instead of, surgery."

The rest. Systemic therapy — treatment that travels through the whole body — may follow, depending on the cancer. Rehabilitation matters. So does steady pain control.

NCI describes the aim of treating metastatic cancer as "to control it by stopping or slowing its growth." Palliative care runs alongside that work. NCI says it acts "to improve the quality of life by relieving symptoms," and that "it can be given at any point during treatment for cancer." Asking for it now is reasonable.

• NIH StatPearls (NCBI Bookshelf) — Spinal Cord Compression
• MedlinePlus — Spinal tumor
• National Cancer Institute — Metastatic Cancer
• Macmillan Cancer Support — Metastatic spinal cord compression (MSCC)
• NHS Scotland — Scottish Palliative Care Guidelines: Malignant Spinal Cord Compression