Metastatic Spinal Tumor :
A spine tumor is an abnormal growth of tissue found in and/or around the spinal column and/or spinal cord. Spinal metastasis is common in patients with cancer. The spine is the third most common site for cancer cells to metastasize, following the lung and the liver.
Symptoms of Metastatic Spinal Tumor :
Early diagnosis of the metastatic spinal disease is important because the functional outcome depends on the neurologic condition at the time of presentation. Back pain, the most common presenting symptom in patients with metastatic tumor to the bone or epidural space, often precedes the development of other neurologic symptoms by weeks or months. However, most back pain is not caused by tumors and not all tumors are symptomatic.
Neurological symptoms, such as weakness, tingling or numbness in the arms or legs may also develop due to a spinal tumor, but these symptoms tend to occur several weeks or months following the onset of back pain.
Patients may experience one or any combination of the following symptoms, and some people with metastatic spinal tumors do not have any symptoms at all. It is important to document symptoms, as they can be used to help diagnose metastatic spinal tumors.
Metastatic Spinal Tumor Pain :
The back pain that is caused by spinal tumors generally tends to be described as severe and not relieved by rest or pain medication. There are a number of types of pain that can be caused by spinal tumor growth.
- Aching pain in the bones: Tumor growth can result in a number of biological responses, such as local inflammation or stretching of the anatomical structures around the vertebrae. These biological sources of pain are often described by patients as a deep ache that tends to be worse at night, even to the point of causing one to wake up from the pain, and/or pain that is worse first thing in the morning after waking up and improves somewhat after getting up and moving around.
- Pain that shoots down the arm or leg: This type of nerve pain, also called radicular pain, travels along the path of the nerve – down the leg if the tumor is in the lumbar spine, or down the arm, if the tumor is in the cervical spine. Radicular pain is often described as burning or shooting pain that follows the path of the nerve into the extremities. Radicular pain may be accompanied by neurological symptoms along the affected nerve, such as weakness, tingling or numbness.
- Pain with movement: If the tumor is growing within the vertebra, the walls of the vertebra can become thin and weaken. If left untreated, the bones can fracture. A vertebral fracture can result in sudden onset pain that tends to be more severe during movement or when placing pressure on the bone, such as when sitting and standing.
Neurologic Dysfunction :
After pain, the next most common symptom of metastatic spinal tumors is neurological dysfunction, such as tingling, weakness and/or numbness, or impaired muscle control in the arms or legs.
Neurological symptoms can occur if the tumor growth or vertebral fracture compresses neurological structures in and around the spine. In addition to nerve symptoms that accompany radiculopathy (as discussed above), potentially serious neurological symptoms may include:
- Cauda equine compression: Significant compression of the cauda equina (bundle of nerves at the base of the spine) may result in varying degrees of bowel or bladder problems, lower extremity weakness and/or loss of sensation in the buttocks. This condition requires immediate medical attention and may require prompt surgery.
- Spinal cord compression: Compression of the spinal cord may result in various degrees of limb weakness and an impaired ability to move limbs.
Other symptoms may include :
- Loss of ability to control the bladder or bowel.
- Instability while walking.
- Diminished sensation, particularly below where the tumor is located.
- Overactive reflexes, such as twitching and spastic tendencies.
- The rapid succession of alternating contractions and partial relaxations.
Metastatic Spinal Tumor Treatment :
There are several considerations that must be examined to determine the best treatment. For many metastatic spinal tumor patients, treatment plans focus mainly on preserving and improving the patient’s quality of life. For others, treatment may focus on the removal of the tumor.
Treatment of metastatic spinal tumors must take into consideration the following:
- Type of cancer
- Number of tumors in the spine
- Location of tumor
- Current cancer treatment
- Life expectancy
- Patient’s quality of life
- Patient’s general condition, including comorbidities such as anemia, diabetes, high blood pressure, etc.
Overall, the patient’s personal preferences and considerations regarding his or her primary cancer are important in deciding how to treat the spinal tumor(s).
The goals of treatment for metastatic spinal tumors are generally :
- Palliative treatments designed to optimize the patient’s quality of life, and to minimize pain and disability, including:
- Pain relief
- Preservation of neurological function
- Prevention of fracture
- Correction of spinal instability
- Improvement of the patient’s general functionality and ability to move/walk
- Support the patient’s ongoing cancer treatments that are designed to bring cancer into remission or to prolong the patient’s life. Debulk, or shrink, the spine tumor to decrease the tumor burden
In general, earlier diagnosis and treatment of spinal tumor symptoms result in a better outcome. Cancer patients who experience the development of new symptoms of back pain and/or limb neurological symptoms should seek immediate medical care.
Nonsurgical treatment of Metastatic Spinal Tumors :
Nonsurgical options are considered first-line treatment for many metastatic spinal tumor symptoms and tumor management. Nonsurgical options vary from medications to radiation therapy.
- Medications: Medications, such as nonsteroidal anti-inflammatory drugs, may be used to reduce pain. Narcotics may be used for short term pain management. Hormonal treatments may be used for metastases that are sensitive to hormones, such as breast and prostate cancer.
- Back braces: Braces may be used for symptom relief when mechanical pain develops as a result of spinal instability. Braces are generally used in combination with other treatments.
- Radiation therapy: Radiation therapy has proven effective in shrinking tumors and is often the treatment of choice for alleviating pain associated with metastatic spine tumors. High levels of radiation energy directed at the tumor can shrink tumor cells, relieving pressure on nerve roots and/or the spinal cord. Studies have indicated a success rate of 70% in alleviating pain. However, it can take up to 2 weeks to feel pain relief.
There are a variety of methods of radiation delivery. For spinal tumors, external radiation therapy methods are used – a machine outside the body delivers radiation to the tumor. Stereotactic radiosurgery uses imaging to target the tumor so that higher doses of radiation can be given with less risk of damage to healthy tissue.
- Ablation: Ablation refers to an energy source that is transmitted locally to the tumor through a needle. Ablation is designed to target and destroy unhealthy tissue (the tumor) while sparing healthy tissue. The goal of treatment is to shrink the tumor to relieve pain associated with pressure on the nerve roots and/or spinal cord.
- Radiofrequency ablation: designed to target and destroy the tumor tissue with heat (radiofrequency energy)
- Cryoablation: designed to use cold gas to freeze and destroy tumor cells.
Primary cancer treatments do not have to be stopped for ablation procedures, and pain relief is often felt in hours/days.
- Chemotherapy: Chemotherapy can be divided into antitumor drugs and drugs that prevent or ameliorate the effects of the tumor. Antitumor chemotherapy currently plays a relatively limited role in the treatment of spinal metastases. Chemotherapy may also be used to kill tumors cells that may remain after surgical removal of the tumor.
Surgical treatment of Metastatic Spinal Tumors :
Surgical removal of a spine tumor is indicated for patients who may benefit from the tumor removal, either in terms of removing cancer and/or lessening any severe symptoms associated with the tumor. There are many types of surgery that may be considered as part of treatment for a spinal tumor. In general, there are two categories of surgery:
- Minimally invasive surgery – surgical approaches that include relatively small incision(s)
- Open surgery – more extensive surgical procedures that require larger incision(s)
Minimally invasive procedures are more commonly performed, although open (more extensive) surgical procedures may be an option in certain cases.
Minimally invasive treatment for spinal tumors :
Surgery is considered minimally invasive when it involves small incisions (e.g. ½ inch) and minimal tissue disruption. Most minimally invasive procedures have relatively short recovery times.
Vertebroplasty and kyphoplasty are also known as vertebral augmentation are typically reliable procedures designed to provide pain relief for patients who have a vertebral fracture associated with a spinal tumor.
- Vertebroplasty: This procedure involves inserting a needle through a small incision in the back so that a medical-grade bone cement can be inserted into a fractured vertebra to fill in the empty spaces and act as an internal cast to stabilize the bone. The treatment is designed to reduce pain, prevent further collapse of the vertebra, and restore the patient’s mobility.
- Kyphoplasty (vertebral augmentation): Kyphoplasty also involves injecting bone cement into a vertebra and involves the additional step of first inserting a balloon into the bone and inflating the balloon to create a cavity. This treatment is designed to stop the pain caused by a spinal fracture and to stabilize the bone via an internal cast.
- Transarterial Chemoembolization: This procedure involves a small incision in the thigh for access to the femoral artery. A catheter guided by a wire is directed through the vascular system to the tumor with the aid of imaging. Once the tumor is located, a chemotherapeutic agent is injected directly into the tumor to shrink or destroy the tumor to remove pressure on individual nerve roots or the spinal cord.
Open surgery for spinal tumors :
In general, extensive surgical procedures (open surgery) are often avoided in patients with metastatic spinal tumors. Patients with metastatic cancer are susceptible to systemic complications, and studies have not proven that survival is extended reliably with aggressive treatment of spinal metastases.
Open surgical procedures for the treatment of metastatic spine tumors are primarily performed on patients who meet the following criteria:
- A life expectancy of more than 6 months
- Only one tumor
- Neurological deficits (such as weakness, loss of muscle control) and/or significant spinal instability
Patients with slow-growing metastatic spinal tumors, such as those resulting from breast or thyroid primary cancers, and those with only one spinal tumor are potential candidates for removal with a curative goal.
It is likely that stabilization of the vertebra is necessary after the removal of the tumor, which can be done at the same time (as part of the same surgery) as the tumor removal.
- Spinal stabilization surgery: The goal of treatment is to stabilize the spine and to reduce any deformity that may have developed. Surgeons will choose the best stabilization method based on tumor type, the extent of bone destruction, general patient condition, and anticipated cancer treatments. There are various surgical approaches as well as stabilization methods available. While the goal of surgery is fusion, treatments for cancer, like chemotherapy, may interfere with the bone healing required to create a fusion. Stability in cases where fusion does not occur relies on solid mechanical fixation from implants such as titanium screws, plates, rods and cages
- Spinal decompression surgery: Operative methods to relieve pressure placed on the spinal cord are classified as follows:
- Corpectomy – removal of the body of a vertebra and the discs
- Laminectomy – removal of a small part of the bony arches of the spinal canal called the lamina
- Costotransversectomy – removal of a part of a rib along with the transverse process of a vertebra
The most suitable method of decompression is selected based on a number of considerations, including the anatomical location of the tumor and general condition of the patient.
In general, surgical treatment is customized to the patient’s overall health condition, the type and stage of cancer, as well as the location, size, and type of spinal tumor(s). Open surgery is relatively rare but can be helpful in certain cases.