Definition and Overview
Chondrosarcoma is cancer that forms on the bones, particularly in cells that produce cartilage. It most commonly affects the axial skeleton and usually attaches itself to the outermost layer of the meninges (dura matter).
Chondrosarcoma cancers belong to a group of cancerous tumours known as sarcomas, which form on bone and soft tissue. It accounts for 30% of all cancers that affect the skeletal system. Although it is a slow-growing cancer, it is challenging to treat due to its resistance to both chemotherapy and radiotherapy.
Chondrosarcoma tumours range from small, low-grade tumours with a low metastatic tendency to high-grade, highly aggressive tumours characterised by early metastases (cancer spread). The tumour's stage is determined using the Enneking staging system, which is also used for musculoskeletal sarcomas. The tumour is also graded based on the following factors:
The microscopic composition of cancer cells
How fast cancer cells are growing
The risk of local invasion
The tendency for metastasis
Grade 1 or low-grade chondrosarcoma are slow-growing, non-invasive, and non-metastatic. Also, the histological appearance of cancer cells is similar to those of normal cartilage.
Grades 2 chondrosarcoma tumours are characterised by rapid cell growth and abnormal-looking cells that are likely to invade nearby tissues.
Grade 3 chondrosarcoma, also known as high-grade dedifferentiated chondrosarcoma, is the most severe form of the disease. This stage is characterised by anaplastic, highly abnormal tumours.
Chondrosarcoma tumours also come in different types, including:
Conventional chondrosarcoma, which accounts for 90% of all chondrosarcoma cases
Mesenchymal chondrosarcoma, a rare but deadly form of the disease that commonly affects the ribs, jaw, femur, skull, and spine.
Extraskeletal myxoid chondrosarcoma
Clear cell chondrosarcoma
Causes of Condition
The primary cause of chondrosarcoma is unknown, but there are several risk factors, such as a previous history or family history of other bone cancers, including osteochondroma or enchondroma.
The risk of chondrosarcoma is also higher among patients who are suffering from certain diseases, namely:
Chondrosarcoma's association with leukemia and glioma is mainly due to faulty isocitrate dehydrogenase 1 and 2 enzymes.
Chondrosarcoma can cause a variety of symptoms, including:
An unexplained mass
Vision and hearing disruption
Pain associated with chondrosarcoma is often deep, dull, and normally gets worse at night. As the condition progresses, patients may also experience nerve dysfunction and reduced range of motion in the affected joints. They also face a greater risk of pathologic fractures.
Unfortunately, all common signs of chondrosarcoma can also be indicative of other health problems. Thus, several tests are performed so doctors can make an accurate diagnosis. These tests include x-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI), and a biopsy.
An MRI is particularly effective in evaluating the extent of chondrosarcoma tumours and assessing the extent of tissue damage. A CT scan, on the other hand, is useful in detecting calcifications in the matrix to confirm a suspected diagnosis. Meanwhile, a biopsy is also an effective diagnostic tool but can be challenging to perform, as it should be done without seeding the biopsy tract with cancerous cells. During this procedure, a small amount of malignant cancer cells is taken from the tumour for closer examination. This can be done using closed biopsy techniques such as fine-needle aspiration or core biopsy, or through conventional open biopsy techniques.
Who to See and Types of Treatments Available
Patients who experience any of the symptoms listed above should consult a general physician or family doctor right away. If there is reason to believe that the patient is suffering from chondrosarcoma, he will be referred to sarcoma specialists or orthopedic oncologists. If the tumour is located in the spine, skull, or near the chest, the patient's medical team will also include a thoracic surgeon or neurosurgeon.
The standard chondrosarcoma treatment is surgery, during which the tumour and a wide margin of healthy tissue around it are removed. Unfortunately, in many cases, tumour removal means amputating the affected body part, which is usually the leg or arm. After the surgical excision of the tumour, patients are often advised to undergo supplementary proton therapy, which has the potential to control tumour growth. Proton therapy is also strongly recommended for patients whose tumours are located in locations that make it difficult for surgeons to completely remove them during surgery.
A more recent addition to the available treatment options for patients diagnosed with chondrosarcoma is induced apoptosis. This can be performed either directly or in conjunction with chemotherapy or radiotherapy.
The stage of cancer at the time of diagnosis, as well as the treatment methods used, have a direct effect on the patient’s long-term chondrosarcoma prognosis. For low-grade chondrosarcomas, the 5-year survival rate is about 90%. Unfortunately, this drops to just 10% when cancer is already in its advanced stages or has metastasised to distant body parts or organs.
“Mesenchymal chondrosarcoma.” Bonetumor.org. http://www.bonetumor.org/tumors-cartilage/mesenchymal-chondrosarcoma
Sei Young Lee, Young Chang Lim, et al. “Chondrosarcoma of the head and neck.” Yonsei Med J. 2005 Apr 30; 46(2): 228-232. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2823018/
Tachino H, Fushiki H, Ishida M, Watanabe Y. “A low-grade condrosarcoma presenting as an unusual cervical mass in the hyoid bone: a case report.” Journal of Medical Case Reports. 2012; 6:21. https://jmedicalcasereports.biomedcentral.com/articles/10.1186/1752-1947-6-21
Chenglei Liu, Yan Xi, Mei Li, et al. “Dedifferentiated chondrosarcoma: Radiological features, prognostic factors and survival statistics in 23 patients.” http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173665