Surgery for malignant and primary spinal column tumors
Tumors of the bony spinal column may require resection and stabilization to improve patient outcome, reduce the risk of paralysis, and reduce pain. Michelle (M) J. Clarke, M.D., a neurosurgeon at Mayo Clinic with specialized training in spinal column and spinal cord tumors, notes that the goal in metastatic spinal tumors is often palliative. The goal in some primary bone tumors, such as chordoma of the spinal column, is to effect a cure.
Metastatic tumor resection
Dr. Clarke points out that the occurrence of metastatic spinal tumors is becoming increasingly common as the number of cancer survivors grows. It is estimated that vertebral masses develop in approximately 40% of cancer patients and 10% to 20% have spinal cord compression. Metastatic spinal tumors can cause fractures, pain, and neurologic dysfunction from spinal cord compression.
Advances over the past 15 years have improved outcomes in the surgical approaches taken to manage metastatic tumors. Often, surgery is followed by adjuvant radiotherapy. The goal of surgery is to reduce pain and improve function by removing the tumor, decompressing the spinal cord, and stabilizing and reconstructing the spine. "The purpose of surgery is to maintain or improve the patient's quality of life," says Dr. Clarke.
At Mayo Clinic, the criteria for surgical candidacy include the type of tumor and the patient's expected survival rate (ie, 3 to 6 months or more) and current functional and overall health status. Occasionally, metastatic tumors are identified before loss of function, but for patients with a sudden onset of weakness or paralysis, the window of opportunity to restore function is very short—usually, less than 24 hours. Patients who live at a distance from Mayo Clinic may be flown to the clinic by Mayo's emergency medical helicopter service for immediate evaluation.
Chordomas are slow-growing primary malignant bone tumors that can reach enormous size. Although far more rare than metastatic tumors, chordomas represent the most common primary malignant tumors of the sacrum and the mobile spine.
Symptoms are often insidious in onset and their cause undiagnosed for months to years, until the tumor becomes so large that it disrupts function. Depending on their location, chordomas can cause:
- Pain and sensory and motor abnormalities
- Bowel, bladder, or sexual dysfunction
- Airway obstruction
- Swallowing difficulties
They can become large enough to compress vital structures, such as the aorta or vena cava.
Perhaps the most important thing about chordomas is that they are encapsulated tumors. Dr. Clarke, who has had specialized training in resecting chordomas, points out that if a neurosurgeon tries to debulk or break the tumor up in surgery, the tumor will spread. If the entire tumor is removed as an intact whole, however, recurrence is less likely.
She adds that anything more than a needle biopsy risks recurrence. Thus, it is critical that the tumor be removed as a single mass, even when the tumor becomes very large. The procedure is provided at only a few medical centers in the world and typically involves a radical en bloc resection.
Depending on the location of the tumor, such a surgery may involve thoracic, orthopedic, cardiac, general, and plastic surgeons in addition to the neurosurgeon. Surgery may be staged and take place over several days, during which the site is prepared, the entire tumor removed in one encapsulated mass, and the spine reconstructed. Such a procedure requires several days of coordinated efforts among multiple team members and, following surgery, the services of a pain management team and rehabilitation specialists.
In addition to problems stemming from their unusual size, chordomas can metastasize to other organs. Without surgery, chordomas are fatal in approximately 50% to 70% of patients. Resecting a large chordoma as an encapsulated whole can be extremely challenging. As Dr. Clarke points out, however, major en bloc resections of this type can be done with the kind of specialized expertise and interdisciplinary team effort that is characteristic of Mayo Clinic's practice.
Although spinal tumor removal may require a major surgical procedure, according to Dr. Clarke, patient surveys show that patients are pleased with the outcome. For patients with chordoma, surgery can be lifesaving. For appropriately selected patients with metastatic spinal tumors, surgery can make a marked difference in quality of life.