Spinal cord compression due to cancer may occur when cancer spreads (metastasizes) to the bones of the spine, and is sometimes the first symptom of cancer. Symptoms usually begin with back pain, that may radiate down the legs or arms, cause weakness or tingling, a band-like sensation in the chest, and/or bladder and bowel problems.
An MRI is the best test to diagnose the condition, though the entire spine should be examined. Treatments may include steroids, radiation, surgery, and more depending on the type of cancer. It occurs most commonly with cancers of the breast, lung, and prostate, though other cancers may cause the condition as well.
The prognosis of spinal cord compression depends on how quickly it is recognized and treated, and the possibility should be considered in anyone who has cancer and develops the new onset of back pain.
Spinal cord compression often occurs as a complication of cancer in people who know they have the disease, but this isn't always the case.
In one study it was found that spinal cord compression was the first sign of cancer in roughly 10 percent of people.
Statistics vary, but it's thought that 5% to 10% of people with cancer will develop spinal cord compression. This number rises to up to 20% of people with metastatic cancer and 40% of people with bone metastases.
As people are surviving longer with cancer than in the past, the incidence is increasing and is expected to increase further. That said, newer treatments that focus on preventing bone metastases from occurring in the first place offer hope that this increase will be smaller than projected.
Cancers That May Lead to Spinal Cord Compression
Spinal cord compression may be a complication of many forms of cancer, but the most common are breast cancer (29%), lung cancer (17%), and prostate cancer.
Other adult cancers often associated with the condition include kidney cancer (renal cell carcinoma), lymphomas, myeloma, thyroid cancer, genitourinary cancers, and digestive tract cancers. In children, spinal cord compression occurs most often with sarcomas and neuroblastomas.
The Spinal Cord
Spinal cord compression occurs most often when cancer spreads to the spinal cord via the bloodstream from other regions of the body, but may also occur when a tumor extends locally. Nerves that exit the spinal cord control motor function (movement), sensation, and in certain regions, bowel and bladder function. They may be affected when a tumor indents, displaces or surrounds, the spinal cord by growing into the epidural space and pressing on the dura (the sac that surrounds the spinal cord).
Compression can occur at any level:
The thoracic region (mid-back) is involved 60% to 70% of the time
The lumbosacral region (lower back) is affected 20% to 30% of the time
The cervical region (neck) is involved in 10% of compressions
The spinal cord ends in the thoracic spine around the first or second lumbar vertebrae, with a collection of nerves, called the cauda equina, below. Cauda equina syndrome is an emergency, not only because of the potential of paralysis but of loss of bowel and bladder function. Multiple areas of the spinal cord may be affected, especially with breast cancer and prostate cancer.
Symptoms and Signs
The signs and symptoms associated with spinal cord compression can arise gradually or occur abruptly. While there are many potential symptoms, the most common is the new onset or worsening of back pain in someone who has cancer, even if the pain seems to have another obvious cause.
Worsening Back or Neck Pain
As noted, the most common symptom of spinal cord compression is the new onset or worsening of pain in the back or neck, with these symptoms occurring in over 90 percent of people with the condition. Initially, the pain can be subtle, and easily dismissed.
The pain may be mild at first and worsen with time. It may become so severe that people are unable to sleep. It often worsens with lying down (in contrast to disc disease), and with weight-bearing, lifting, coughing, sneezing, and when bearing down to have a bowel movement. Early on, the pain may be localized to the spine, but eventually, radiate to the arms or legs if there is compression on the nerve root (radiculopathy).
That said, it can be difficult to distinguish pain due to malignant spinal cord compression from benign causes, and it should always be evaluated.
Weakness in Arms or Legs
Motor weakness is the second most common symptom (80 percent) of cord compression. Initially, the legs or arms may feel heavy or like they may give out. In time, weakness can lead to unsteady walking or loss of balance. Sometimes, when the compression is acute and severe, it can cause complete paralysis (spinal shock).
Numbness of Pins and Needles Sensation in Arms or Legs
Spinal cord compression can also affect sensory nerves, nerves that transmit information about touch, pain, vibration, and temperature. People may notice numbness or tingling (pins and needles sensations) in their arms, legs, perineum, or buttocks. If symptoms come on gradually, sensory changes may only be noted on a physical examination.
Band-Like Feeling Around the Chest or Abdomen
When compression of nerve roots in the thoracic spine (the most common site of compression) is bilateral, it can cause a tight band-like sensation around the chest or abdomen. When severe, this can cause a feeling of suffocation or a feeling that is difficult to draw in an adequate breath.
Bowel and/or Bladder Problems
The nerves that travel out from the lower spine (cauda equina) control bladder and bowel function. Bladder function is usually affected first and may result in symptoms of inability to pass urine, or on the other end of the spectrum, incontinence. Bowel symptoms may include constipation or fecal incontinence. Nerve compression is this region may also lead to loss of sensation in the pelvic region, and erectile dysfunction in men.
Causes and Risk Factors
Malignant spinal cord compression is usually caused by cancers that spread to bones such as:
Lung cancer with bone metastases
Breast cancer with bone metastases
Risk factors for spinal cord compression include cancers that commonly spread to bones. For example, with breast cancer, nearly 70 percent of people with metastatic breast cancer have bone metastases. They are more common in women who have invasive ductal carcinomas of the breast than lobular carcinomas, in which tumors that are estrogen and progesterone-receptor positive.
With all cancers, the risk of spinal cord compression is higher for tumors that are more aggressive and are diagnosed at more advanced stages of the disease.
The diagnosis of spinal cord compression should begin with a high index of suspicion, and an evaluation of any new back pain in a person who has known cancer (even if it appears to be in remission).
Initial workup includes a careful medical history, with particular emphasis on a diagnosed cancer, or risk factors or symptoms of cancer in those who have not been diagnosed.
A physical exam is then performed with attention focused on the function of spinal nerves via a neurological exam including tests of coordination and reflexes. People who have spinal cord compression may have pain with straight leg raises (raising legs while lying on the back), to palpation over the area in question, or with flexion of the neck. Reflexes may be increased or decreased depending on the level of the compression.
One sign, Lhermite's sign, maybe a sign of early cord compression. It involves the presence of a tingling/electrical sensation that shoots down the arms, legs, or back when the neck is flexed or extended.
To evaluate the involvement of nerves supplying the bladder, a catheter may be placed into the bladder after urinating. The return of more than 150 CCs of urine suggests nerve compression.
Imaging is extremely important in diagnosis, but it's important that the diagnosis is not delayed and time not wasted by studies that may not reveal the cause (such as regular X-rays of the spine).
Most physicians recommend going directly to an MRI of the spine if there is any question. Since spinal cord compression can occur at more than one level (especially with breast and prostate cancers, and as many of 50% of people with cancer have evidence of cancer at more than one level), the whole spine should be imaged.
For those who cannot have an MRI (such as those who have metal in their body from a pacemaker or joint replacement), a CT scan should be done, again looking at the whole spine. If either an MRI or CT is not available, or if the results aren't clear, a CT-based myelogram may be needed.
Signs that compression is present or may be imminent may be seen on a bone scan or PET scan, but these tests can't diagnose the condition.
A biopsy of cancer in the spine is usually not necessary unless spinal cord compression is the first sign of cancer. In this case (with a cancer of unknown primary origin), a biopsy may be needed to determine the source of the primary tumor.
There are a number of non-cancer related causes of spinal cord compression, that may occur even in people with cancer. These include conditions such as:
Disc disease (especially with cauda equina syndrome)
The collapse of a vertebra due to osteoporosis (vertebral compression fracture)
Infection or abscess
There are also potential causes of spinal cord compression related to cancer but not due to metastatic disease to the spine such as:
Radiation myelopathy (damage to the nerve roots from radiation treatments)
Invasion of cancer into a neural plexus (collection of nerve roots) called plexopathy
Spinal cord compression needs to be treated urgently and should be started as soon as spinal cord compression is suspected. The goals of treatment are both to relieve pain and to restore function. Options include:
As soon as spinal cord compression is suspected, your doctor may have you lie flat on your back until further testing is completed in order to prevent further damage. A cervical collar or back brace may also be used.
Corticosteroids (usually dexamethasone) are usually started right away, even before the diagnosis is confirmed, in order to decrease swelling.
The most common treatment used for spinal cord compression is external beam radiation therapy. It may also be given after surgery. It may be given as a single treatment, or instead, daily for a week or two.
Proton beam therapy is another option that provides similar results. If only a small area of the tumor is causing the problem, high dose radiation therapy to a small region of tissue (stereotactic body radiotherapy), also called SBRT or cyberknife may be used.
Surgery may be used instead of or along with radiation therapy for some people. Indications for surgery include:
If the primary cancer is unknown. If primary cancer hasn't been identified, surgery and biopsy may be used to determine the type of cancer.
If it is a type of cancer that doesn't respond well to radiation therapy. Tumors such as melanomas, sarcomas, or kidney cancer may not respond to radiation.
If a person has had previous radiation therapy to the area.
If a fracture/dislocation is present and stabilization is needed.
If symptoms (neurological deterioration) are progressing very rapidly (could be a vertebral burst fracture).
If spinal cord compression recurs after radiation.
If neurological signs or spinal instability are present in younger people with a relatively good prognosis.
Surgical approaches may include decompression laminectomy (removing a section of bone to remove pressure), vertebroplasty/kyphoplasty (injecting cement into the vertebrae to add stability), using rods or a bone graft, and debulking of the tumor. In some cases, however, surgery could lead to destabilization of the spine.
General Treatments for the Metastatic Cancer
General treatments for metastatic cancer are often used, but many of these do not reduce the size of the metastases rapidly enough to prevent further damage. For men who have prostate cancer and who have not had androgen deprivation therapy (hormone therapy), this is usually combined with radiation therapy and/or surgery.
Chemotherapy drugs may be useful along with radiation and/or surgery, especially with cancers such as non-Hodgkin's lymphoma and small cell lung cancer. Targeted therapies and immunotherapy may also be used, as well as hormone therapy in women with breast cancer.
Specific Treatments for Bone Metastases
Specific treatment for bone metastases may also be used in addition to management of spinal cord compression, especially with cancers of the breast and prostate, lymphomas, and myelomas. Bone-modifying drugs such as bisphosphonates and the monoclonal antibody denosumab may help treat pain from bone metastases as well as decrease the risk of further metastases occurring.
Bone metastases can be very painful, and adequate pain control is an extremely important goal of treatment. Some physicians recommend a palliative care consult with a team of physicians and other specialists who focus on maximizing the quality of life with cancer.
Physical therapy can be helpful if any weakness is present, and working with an occupational therapist may help people overcome some of the challenges posed by sensory dysfunction.
With bowel or bladder symptoms, a catheter may be needed, as well as medications to manage constipation. Careful attention to reducing the risk of blood clots (common in people who have cancer) is also important.
The prognosis of spinal cord compression depends on many factors, including the type of cancer, wherein the vertebral column the compression occurs, and how long it has been present.
The restoration of function, in particular, is very dependent on how quickly treatment takes place.
For those who are able to walk before treatment, 75 percent will retain the ability to walk. In contrast, for those who are unable to walk when they present for treatment (have paralysis), only 10 percent will recover full function. In other words, treatment can clearly improve outcomes, and this is critical as at least a third of people will survive for a year or more.
The life expectancy after spinal cord compression varies, and often depends on the course of underlying cancer. For people with breast cancer (even with spinal cord compression), bone metastases carry a better prognosis than metastases to other regions of the body, and some people may live several years after treatment.
In people with lung cancer who are treated with targeted therapies and bone modifying therapies after spinal cord compression, both survival rate and quality of life improved.
With some cancers such as breast cancer and prostate cancer, drugs may be used to try to prevent the development of bone metastases in the first place, and this is the theory behind the recent recommendation to include bisphosphonates for early-stage breast cancer treatment. When bone metastases are present, bone-modifying drugs may help reduce further bone metastases and possibly the development of spinal cord compression.
Certainly, treatment of underlying cancer may reduce the risk, and many new options are available for controlling advanced cancers. That said, it's important to be your own advocate in your cancer care to ensure you get the best care possible.
A Word From Verywell
Spinal cord compression as a complication of bone metastases is a medical emergency, but prompt treatment cannot only reduce the risk of permanent problems (such as paralysis) but can often improve both survival rate and quality of life. An awareness of potential symptoms, especially the new onset of back pain, and a high index of suspicion (especially for those who have known bone metastases), with immediate MRI (or alternative when not possible) if present, are extremely important in reducing the complications from this common problem.