What is Chordoma?
Chordoma is a rare malignant bone tumor. A group of cells known as the notochord come together during the fourth through six weeks of fetal development. The notochord serves as the base for the development of the spinal cord. As the spinal cord forms, the notochord disappears, except for parts that form part of the discs between the vertebrae. Chordomas form from parts of the notochord that don’t break down as they should. Over time these leftover cells can change and become malignant. Harris Center researchers are studying these changes to develop new therapies for chordoma. Chordoma primarily spreads by local invasion, but it does have the potential to spread to the lungs, bone and liver.
Most develop at the base of the skull, the base of the spine or tailbone, but they can occur in other areas of the spine. Tumors at the base of the skull most commonly appear between the ages of 35-40. Those that arise from the sacrum usually appear between the ages of 50 and 70. Chordoma can occur in children but it is more common in adults. Approximately 300 new cases of chordoma are diagnosed in the US each year. Chordoma occurs more frequently in men. There are no known risk factors for chordoma.
What are the Symptoms of Chordoma?
Pain and changes in sensation or function are the most common symptoms of chordoma. Tumors located at the base of the skull may cause headache, neck pain, difficulty swallowing, or double vision. Chordoma in other areas of the spine may cause pain, numbness or weakness in the arms or legs. Changes in bowel or bladder function may occur.
The symptoms are similar to those caused by other disorders and chordoma grows very slowly, so patients may have symptoms for more than a year before seeking treatment.
How is Chordoma Diagnosed?
Abnormalities are usually evident during a neurological examination, but imaging studies are needed. Magnetic Resonance Imaging (MRI) is the most useful test. In addition, a Computed Tomography (CT) study may be done to rule out spread of chordoma to other areas of the body. To make the final diagnosis, a biopsy is usually required.
Because Chordoma develops close to vital structures in the central nervous system, treatment is complex and can be difficult, but the prognosis is not always grim. In a recent study, Harris Center clinicians achieved a five-year continuous disease-free survival rate of 62.5% with primary sacral chordoma.
Click here for the PubMed summary of a recent paper by Harris Center clinicians on the efficacy of chordoma surgery performed in concert with proton-beam therapy.
The primary treatment for chordoma is the complete surgical removal of the tumor. To ensure the best outcome and prevent the spread of chordoma , the surgeon(s) must remove the chordoma and a margin of normal tissue surrounding it. The result of the first surgery is critical in determining the patient’s prognosis (outcome) It is vital that an experienced, expert team of surgeons perform the initial operative procedure.
Skull based chordoma are generally removed through minimally invasive surgery by highly trained, skilled surgeons. Patients with chordoma at the base of the skull following this procedure usually require a brief hospital stay.
Chordomas that occur in the cervical, thoracic, lumbar or sacral spine have a larger area to grow requiring a more extensive operative procedure to remove them.At the Harris Center the surgeons perform the operative procedure in one or two stages depending on the size and location of the tumor. The surgeons are acutely aware of the risks in chordoma surgery. Every precaution is taken to avoid spread of tumor in the surgical wound. The use of preoperative radiation therapy by Harris Center radiology oncologists helps to avoid this complication.
Sacral chordomas, those in the lower spine, may involve nerves that control the bowel and/or bladder function. Most patients are able to manage control using a bowel regime and/or intermittent catheterization. A colostomy may be indicated if the size and location of the chordoma requires the sacrifice of nerves that control bowel function.
The multidisciplinary approach continues throughout the patient admission including general surgical oncologists; thoracic surgeons; ear, nose and throat specialists (ENT); and reconstructive surgeons; neurological surgeons; orthopaedic oncology surgeons; radiation oncologists; orthopaedic pathologists; medical oncologists; and clinical nurse specialists; social workers; physical therapists; and occupational therapists working as a disciplined team to achieve the best possible outcome for the individual patient.
Surgical intervention for the removal and treatment of cervical, thoracic, lumber or sacral chordoma by and large requires a hospital admission of 3-10 days and likely follow-up rehabilitation in a hospital or specialty facility.
Radiation Therapy for Chordoma
Pre and/or postoperative radiation therapy has improved local control of chordoma. It can also slow the growth of the tumor if it has been incompletely resected or if it has recurred.
Proton beam therapy uses energy from protons of atoms to destroy cancer cells. It can be aimed at a tumor very precisely and can be concentrated on the tumor with little harm to the surrounding tissue.
For some patients for whom surgery is not a good option, high-dose radiation with a combination of x-rays and protons has been able to control tumors for over a decade and may be an important option for them.
Chemotherapy has not proved effective in the past, but there are a number of clinical trials with new agents currently underway.