Overview of Chordoma

Chordoma is a rare, slow-growing bone cancer that affects 1 to 3 per 1 million people every year. They usually affect individuals older than 50 and are slightly more common among men.

Chordomas most commonly occur in the base of the skull (skull base chordoma), or at the lowermost end of the spine in the sacrum (sacral chordoma). They can also be found in the other parts of the spine.

Although chordomas are slow growing, they are malignant tumors that can cause significant damage to surrounding structures. In some cases, they can even spread to other parts of the body such as the lungs and bones, in a process known as metastasis.

Chordomas develop from cells left over from embryonic development, called notochordal cells. The notochordal cells are a part of an embryonic structure called the notochord, which is a rod-like structure that supports the baby during its development in the womb.

Alterations in several genes such as the brachyury gene, SMARCB1, PTEN, and CDKN2A have been associated with the development of chordoma. There have been a few reports of chemicals used in plastic, such as vinyl chloride, as well as radiation being associated with chordomas. However, risk factors usually cannot be identified in most chordoma patients.

Although chordomas generally do not run in families, a few hereditary conditions such as hereditary multiple exostoses, familial chordoma, and tuberous sclerosis have been known to be risk factors for developing a chordoma.

If you have a family history of chordoma or carry a genetic condition that predisposes you to developing the disease, it's crucial to inform your physician. Your doctor may recommend genetic counseling and testing, along with periodic screenings for early detection of cancer. 

Chordomas are often diagnosed late because symptoms do not appear right away. Chordomas are slow-growing tumors that may grow for years before causing symptoms. The symptoms caused by chordomas are mainly determined by the location and the size of the tumor.

Sacral chordomas can cause a number of symptoms:

• Pain in the lower back, which can radiate to the legs
• A hard swelling in the lower back if the tumor is large enough
• Weakness in the legs because of the tumor pressing on the nerves supplying the legs
• Difficulties with bowel movements and urinary control
• Sexual dysfunction, including difficulty in arousal, achieving or maintaining an erection, or ejaculation problems

Skull base chordomas can cause:

• Headaches
• Double vision, known as diplopia, or other visual disturbances
• Hearing loss or ringing in the ears
• Facial asymmetry
• Difficulties with speech and swallowing
• Nasal bleeding, clear watery discharge from the nose, or nasal blockage
• Difficulty breathing
• Hoarseness of voice

These symptoms, alone or in combination, can be caused by numerous other conditions, so see your doctor to confirm the diagnosis.

End-stage chordoma refers to a chordoma that has reached an advanced and uncurable state. The term "end-stage" implies that the cancer has reached its final phase, and that recovery is unlikely.

Chordomas that are "end-stage" may cause pain that is difficult to manage using over-the-counter medications. Your healthcare team will make every effort to ensure you receive adequate pain relief, allowing you to maintain a good quality of life.

As the tumor grows and spreads, everyday activities such as walking, standing, or sitting for long periods may become difficult because of compression of nearby structures. This can also lead to breathing, swallowing, and bowel or bladder control difficulties.

In some cases, the tumor may metastasize, or spread, to other parts of the body, resulting in the development of new tumors. The likelihood of metastasis is determined by several factors, including the tumor's size, location, and subtype. Early identification and treatment are essential to limit disease spread.

Symptoms of metastasis depend on the location of the secondary tumor, but can include fatigue, weight loss, pain, and difficulty breathing.  Palliative care can help manage symptoms and improve overall quality of life in these cases.

Although cancer therapies have made significant strides, treatment options for end-stage chordoma remain limited. Surgery may be possible in some cases with the goal being to alleviate symptoms rather than to provide a cure.

Radiation therapy and chemotherapy may be used to slow tumor growth, however, they can come with potential side effects that may impact overall quality of life. It is crucial for patients and their families to understand when the chordoma has reached an advanced state, and to discuss further management with the healthcare team based on their goals of care.

A combination of imaging tests, physical examination, and biopsy are typically used to diagnose chordomas. During the physical examination, your physician will primarily evaluate your neurological function, including vision, balance, and coordination.

Imaging tests such as a computed tomography (CT) scan or magnetic resonance imaging (MRI) are used to create detailed images of the internal structures of the body. These images can assist in differentiating a chordoma from other types of tumors, such as a meningioma, which may have similar imaging appearances. These imaging tests can also aid in determining the tumor's location, size, and whether it has spread to other parts of the body.

If the imaging results suggest a chordoma, a biopsy may be conducted to confirm the diagnosis and determine the type of cancer. Chordomas are uncommon and can sometimes be misdiagnosed. Therefore, it is important to consult an experienced neurosurgeon for a precise diagnosis.

There are three main types of chordoma based on the World Health Organization (WHO) classification. This classification takes into account the appearance of the tumor observed under the microscope and its molecular characteristics.

• Conventional: The most common form of chordoma that is typically grows slowly.
• Dedifferentiated: Rare subtype that is often more aggressive than conventional chordomas, meaning that they grow faster and have a higher tendency to metastasize.
• Poorly differentiated: Another rare subtype that acts more aggressively than conventional chordomas, but is more common among younger individuals and those with skull base or cervical spine tumors. This is a newly recognized type of chordoma presented in the 2020 WHO classification system.

Receiving a diagnosis of chordoma can be emotionally taxing. Remember that seeking help is a strength, not a weakness, and allowing others to be there for you creates an opportunity for growth and connection. Ask for support and lean on those who care about you. Additionally, do not hesitate to seek a second opinion from a neurosurgeon who is experienced in treating chordomas.

• Although chordomas are slow growing, they are a malignant bone cancer that can cause significant damage to surrounding tissues and organs.
• Risk factors cannot be identified for most chordoma patients.
• Symptoms can be numerous and variable based on the size and location of the tumor.
• The type of chordoma is important in determining treatment strategies and predicting the outcome of treatment.

• National Cancer Institute: Chordoma
• Chordoma Foundation
• NIH Genetic & Rare Diseases (GARD) Center: Chordoma
• Cancer Net
• American Cancer Society