Chordomas in children and adolescents comprise <5% of all chordomas and most frequently develop in the base of the skull or at end of the spine (in the sacrum or the coccyx [the tail bone]) with about equal frequency. The cells that give rise to chordoma come from the notochord. The notochord is an important structure in the early embryo that disappears before birth. However, even after birth, some cells from the notochord remain in bones at the base of the skull, in vertebrae, and in the tail bone. Rarely, one of these cells, which are called notochord remnants, undergoes changes that give rise to a chordoma.
In the United States, there are around 300 new cases of chordoma diagnosed each year. Based on this statistic, the annual incidence of chordoma is approximately one new case per million people per year. The incidence in Europe appears to be similar, but is unknown in other continents. Chordomas account for about 3% of all bone tumors and about 20% of primary spinal tumors. Chordomas are the most common tumor of the sacrum and cervical spine.
What are the signs and Symptoms?
The most common signs of chordoma are pain and neurological changes. Skull base chordomas most often cause headache, neck pain, diplopia (double vision), or facial nerve palsy (paralysis of facial muscles). Chordomas of the spine and sacrum can cause changes in bowel and/or bladder function, pain, aching, tingling, numbness, or weakness of the arms and legs. Often sacral chordomas do not cause symptoms until the tumor is quite large and sometimes a lump is the first sign of a sacral chordoma.
What is the treatment for Chordomas?
Currently, surgery is the first-line treatment for chordomas. Complete resection (removing the entire tumor) during the first surgery provides the best chances for local control and long-term survival.To achieve a complete resection, aggressive surgery is often required and can lead to significant complications or side-effects.
The goal of surgery should be to remove as much of the tumor as possible without causing unacceptable harm. Because outcome and prognosis are largely dependent on the success of the initial surgery, before having any operation it is very important to get multiple opinions from surgical teams who have experience treating chordomas on a regular basis. Some medical centers have multidisciplinary teams of experts who review cases and can help create a coordinated treatment plan for patients with chordomas.
Treatment of patients with chordoma of the skull base is a challenge for neurosurgeons. Because of the origin of the tumor from the bone at the base of the skull, exceptionally complete resection can be achieved. Microscopic total removal of chordoma frequently is followed by the finding of residual tumor in the postoperative computerized tomography and MR images. The recurrence rate, even after radical resection, remains high. The deep localization of chordomas at the middle of the skull base makes surgical access to these tumors difficult; nevertheless, many approaches lead to the clival from the superior, anterior or lateral view. The patterns of spread of the skull base chordoma preclude the use of a single surgical approach. Approaches to chordomas of the skull base should be based on the characteristics of growth in each case, and sometimes two or more skull base procedures may be necessary to achieve a radical removal. Extensive excision has an important role in the treatment of skull base chordoma; however, sometimes unacceptable procedure-related morbidity may occur. Currently, many authors consider that most cases of chordoma should be treated with resection. The average survival for patients with untreated chordoma is estimated to be 28 months after the onset of symptoms.32 Survival after surgery or radiation therapy, or both, ranges from 3.6 to 6.6 years, and all tumors are seen to recur with time.[ On average, recurrence is observed from 2 to 3 years after primary treatment, but sometimes the tumor recurs more than 10 years after initial treatment.
In many cases, radiation therapy following surgery is recommended and can improve chances of local control and survival. Because chordomas do not grow rapidly, high doses of radiation are required to kill the tumor cells. Chordomas that are close to critical structures (arteries, brain, brainstem, cranial nerves, dura, spinal nerves), often limit the dose of radiation that can be safely delivered to the tumor. In most cases, proton beam radiation can maximize the dose of radiation to the tumor, while sparing adjacent critical structures. Intensity modulated radiation therapy (IMRT), stereotactic radiosurgery (CyberKnife® or Gamma Knife®) and carbon-ion radiotherapy are also sometimes used to treat chordoma.
You may be wondering about chemotherapy to kill the tumor cells,but it has been found that this treatment has not been very effective in most patients with chordoma tumors. There is hope because clinical trials are going on to find a successful chemotherapy drug.
For more information : /www.chordomafoundation.org/chordoma/