Chordoma, also known as notochordal sarcomacancer arising from bones and/or soft tissue, is a rare type of cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs that develops from the notochord, a tissuea group of cells that work together to perform a function in the embryo that helps in the development of the spine. The notochord is usually replaced by vertebrae by the time we are born, but some notochord cellsthe basic structural and functional unit of all living things may remain behind. In rare cases, these cells can become cancerous.
The spine is made up of five main areas: cervical, thoracic, lumbar, sacral, and coccyx. The cervical spine encompasses the first seven vertebrae, and is located between the base of the skull (clivus) and the neck. The thoracic spine, or middle back, is made up of 12 vertebrae, and runs from the end of the cervical spine. The lumbar spine, or lower back, is made up of 5 vertebrae, and runs from the bottom of the thoracic spine down to the sacrum. The sacrum is made up of five vertebrae, and forms a triangle to connect to the hips. After the sacrum is the coccyx, or tailbone, which is made up of four vertebrae.
Most chordomas develop in the sacrum, and are known as sacral tumours. Less commonly, it develops at the top of the cervical spine in the clivus, and are known as clival tumours. In rare cases, they can develop in the mobile spine, which is made up of the cervical, thoracic, and lumbar vertebrae.
Chordomas are more commonly diagnosed in males, and are generally diagnosed between the ages of 40-60. However, anyone can develop this disease.
Types of Chordomas
There are three primary types of chordoma, which are categorised by their cellular appearance under the microscope.
Conventional Chordoma
Conventional chordomas, also known as classic chordomas, are the most common subtype of this disease. They are categorised by ‘bubbly’ appearing cells, and the expression of the brachyury protein, which is responsible for regulating the activity of other cells. Conventional chordomas are often slow growing, rarely aggressive, and can have a good prognosisto predict how a disease/condition may progress and what the outcome might be.
Chondroid Chordoma
Chondroid chordomas are a subtype of conventional chordomas, and are defined as conventional chordomas with the presence of cartilage cells within the tumoura tissue mass that forms from groups of unhealthy cells. These types of tumours are often found in the clivus, but can develop in other places. Chondroid chordomas are often slow growing, rarely aggressive, and often has the best prognosis of all chordomas.
Dedifferentiated Chordoma
Dedifferentiated chordomas are a very rare subtype of chordoma. It is characterised by properties of both conventional chordoma cells with brachyury protein and high-grade sarcomas without brachyury protein. Dedifferentiated chordomas tend to me more aggressive than conventional chordomas, are more likely to metastasise, and may not have as good of a prognosis.
Poorly Differentiated Chordoma
Poorly differentiated chordomas are a very rare subtype of chordoma that has only recently been recognised. It is characterised by a genetic mutation, or more specifically, the deletion of the SMARCB1/IN1 (or IN1) protein, which is thought to be a tumour suppressor. Unlike most chordomas, this subtype is more common in children and young adults. These tumours are typically found in patients with a clival or cervical tumour. Poorly differentiated chordomas are generally more aggressive than other subtypes, is more likely to metastasise, and may not have as good of a prognosis.
Treatment
When cancers are detected, they are staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you. However, because of how rare chordomas are, there is currently no standard staging and grading system for this disease. Instead of staging and grading, your doctor will recommend a treatment plan based on the following factors:
- Cancer location.
- Whether or not the cancer has metastasised.
- Your age.
- General health.
- Your treatment preferences.
Your doctor may also recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment options for chordomas may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence to remove as much of the tumour as possible (it may be difficult to remove the entire tumour as it may be close to critical structures, such as nerves, bloodthe red bodily fluid that transports oxygen and other nutrients around the body vessels, and the brain).
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Targeted therapymedication that targets specific molecular features of cancer cells.
- Immunotherapya treatment that uses a person's immune system to fight cancer.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Because of how rare chondromas are, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease. However, it has a potential link to genetic mutations of the brachyury and tuberous sclerosis complex (TSC1 and TSC2) genes.
Symptoms
The symptoms of a chordoma generally vary based on the location of the tumour.
Symptoms of Chordoma in the Clivus
Symptoms of a chordoma in the clivus may include:
- Headaches.
- Double vision.
- Facial pain.
- Changes in hearing.
- Difficulty swallowing.
- Dizziness.
- Neck pain.
- Changes in facial sensation.
- Changes in the voice and/or speech.
Symptoms of Chordoma in the Spine and Sacrum
Chordomas of the spine and sacrum may appear asymptomatic in the early stages of disease. As the cancer progresses, some of the following symptoms may appear:
- Changes in bowelportion of the digestive system that digests food (small bowel) and absorbs salts and water (large bowel); also called intestines and/or bladdera hollow, muscular sac in the pelvis that stores urine function.
- Back pain.
- Back aches.
- Numbness and/or tingling in the back.
- Weakness in the arms and/or legs.
- Impotence.
- Changes in mobility.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have a chordoma, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
